What to Do After Abnormal Private Blood Test Results

Private blood tests can be useful. They can help you check cholesterol, vitamin levels, hormones, thyroid function, liver function, kidney function, inflammation markers, blood sugar and many other areas of health. They can also give you faster access to information when you are worried, curious or trying to understand symptoms.

But there is one difficult moment that many people are not prepared for: the result comes back abnormal.

You may see a red flag, an arrow, a result outside the reference range, or a phrase such as “high”, “low”, “borderline”, “abnormal” or “requires clinical correlation”. It can be alarming, especially if you bought the test yourself and do not have a doctor sitting in front of you to explain what it means.

The most important thing to know is this: an abnormal blood test result does not automatically mean you have a serious illness. But it should not be ignored either. The right next step depends on what is abnormal, how abnormal it is, whether you have symptoms, your medical history, your medicines and whether the sample was collected and processed correctly.

This guide explains what to do after abnormal private blood test results, when to seek urgent help, when to speak to a GP, when to repeat a test, and how to avoid common mistakes.

Important: This article is for general information only. It cannot diagnose you or tell you whether your result is safe. If you have severe symptoms, feel very unwell, or have been told a result is urgent, seek medical help straight away.

First: do not panic, but do take it seriously

Abnormal private blood test results are common. Blood tests use reference ranges, and a reference range is not the same as a perfect health boundary. A small number outside the range may be temporary, expected or not clinically important. In other cases, a result outside the range can point to something that needs follow-up.

One of the biggest problems with private testing is that people often receive results before they receive proper interpretation. You may have a PDF report, a dashboard, a coloured traffic-light system or a short comment, but not the full clinical context. That context matters.

For example, a mildly raised liver enzyme might be due to alcohol, recent exercise, fatty liver, medication, a viral illness or something else. A low vitamin D result is common in the UK and usually managed very differently from a dangerously high potassium result. A borderline thyroid result may need repeating, while a very abnormal kidney result may need prompt medical review.

So the first step is not to assume the worst. The first step is to work out whether the result is urgent, significant, borderline or possibly affected by the way the test was taken.

Step 1: check whether you need urgent medical help

Most abnormal private blood test results are not emergencies. But some results can be urgent, especially if they are very abnormal or you also have concerning symptoms.

Seek urgent medical advice now, using NHS 111, an urgent treatment centre, your GP out-of-hours service or 999 depending on the severity, if you have an abnormal result and any of the following:

chest pain, pressure, tightness or pain spreading to the arm, jaw, neck, back or stomach
severe shortness of breath
new weakness, facial drooping, speech problems, confusion or stroke-like symptoms
fainting, collapse or severe dizziness
severe abdominal pain, especially with vomiting or feeling very unwell
black stools, vomiting blood or heavy unexplained bleeding
severe dehydration, inability to keep fluids down or very reduced urination
yellow skin or eyes with feeling very unwell
severe headache with confusion, weakness, neck stiffness or visual changes
new irregular heartbeat, severe palpitations or feeling like you may pass out
a result that the testing provider has specifically described as urgent or critical

You can use NHS 111 online if you are unsure what level of help you need. Call 999 if symptoms are severe or could be life-threatening.

Some blood results can be particularly urgent when very abnormal, such as potassium, sodium, kidney function, calcium, haemoglobin, white blood cells, platelets, blood sugar, troponin, D-dimer or clotting results. This does not mean every abnormal result in these areas is an emergency, but it does mean you should not sit on a very abnormal result without advice.

Step 2: read the result properly, not just the colour flag

Private blood test platforms often use colour coding. Green may mean within range, amber may mean borderline, and red may mean outside range. These systems are easy to understand, but they can also oversimplify.

When reading your result, look at:

the actual number
the unit of measurement
the laboratory reference range
whether the result is slightly or significantly outside range
whether the test was fasting or non-fasting
whether the sample was finger-prick or venous
whether there were any sample quality warnings
whether previous results show the same pattern
whether you have symptoms that fit the result

A result just outside the reference range is usually interpreted differently from a result several times above or below the range. For example, a very small change in a liver enzyme may be monitored or repeated, while a result many times higher than normal may need faster investigation.

If you are new to reading blood reports, our guide How to Understand Blood Test Results explains reference ranges, units, high and low markers, and why results need context.

Step 3: check whether the sample could have affected the result

Before assuming that an abnormal result reflects a health problem, think about whether the sample or timing could have affected it.

This is especially important with private and home blood tests, where samples may be collected by finger-prick, posted to a laboratory, delayed in transit or taken without a clinician present.

Finger-prick samples can be more vulnerable to collection issues

Finger-prick blood tests can be convenient, but they can be affected by poor blood flow, squeezing the finger too hard, clotting, insufficient sample volume or contamination with tissue fluid. Some markers are more sensitive to these problems than others.

If a finger-prick result is surprising, very abnormal or does not match how you feel, it may need repeating with a venous blood sample taken from a vein.

Haemolysis can distort some results

Haemolysis means red blood cells have broken down in the sample. This can happen during or after collection. It can affect certain markers, including potassium and some liver or muscle enzymes.

If your report says the sample was haemolysed, clotted, insufficient or unsuitable, the result may not be reliable. Ask the provider whether the test should be repeated.

Timing matters

Some blood tests vary by time of day. Testosterone and cortisol are two examples where morning testing is often important. Some hormone tests are affected by menstrual cycle timing. Triglycerides can be affected by recent meals. Blood sugar may be affected by fasting status, recent food, illness or medication.

If the sample was taken at the wrong time, the result may still be useful, but it may not answer the question you were trying to ask.

Recent exercise, alcohol or illness can affect results

Hard exercise before a test can affect muscle enzymes, liver enzymes and inflammation markers. Alcohol can affect liver tests and triglycerides. Recent infection can affect full blood count, CRP, ferritin and other inflammatory markers.

If you tested while recovering from illness, after heavy exercise, after alcohol, or during a stressful period, your clinician may recommend repeating the test when things have settled.

Step 4: decide whether the result is mild, moderate or very abnormal

One useful way to think about an abnormal result is to ask: how abnormal is it?

A borderline result may only need a repeat test, lifestyle changes or review alongside symptoms. A moderately abnormal result may need GP follow-up and additional tests. A very abnormal result may need urgent or same-day advice.

There is no universal rule because each marker is different. A tiny change in one test may matter, while a larger change in another may be less concerning. But as a general principle, the further a result is from the reference range, the more important it is to get proper interpretation.

Also remember that some results are interpreted as patterns. For example, thyroid-stimulating hormone, free T4 and sometimes free T3 are usually interpreted together. Liver tests are read as a group. Kidney function is assessed using creatinine, eGFR and sometimes urine albumin-to-creatinine ratio. Iron status is better understood by looking at ferritin, haemoglobin and other blood count markers together.

For specific result guides, you may find these helpful:

Step 5: contact the private testing provider

If you paid for a private blood test, check what support is included. Some providers only supply laboratory results. Others offer comments from a doctor, nurse, pharmacist or clinical scientist. Some offer follow-up appointments at extra cost.

Ask the provider:

Was the sample suitable and processed correctly?
Were there any sample quality issues, such as haemolysis or clotting?
Is the result mildly abnormal, significantly abnormal or urgent?
Do they recommend a repeat test?
Should the repeat test be venous rather than finger-prick?
Does the result need GP review?
Can they provide a clinician-reviewed report you can share with your GP?
Was the laboratory UKAS-accredited for the relevant tests?

In the UK, laboratory quality matters. UKAS accreditation is an important sign that a medical laboratory has been assessed for competence, quality systems, staff, equipment and testing processes. You can read more from UKAS information for patients.

If a provider cannot explain whether a result is clinically important, or if their advice is vague, it is sensible to speak to your GP or another qualified clinician.

Step 6: speak to your GP when needed

You should contact your GP surgery if your private blood test result is abnormal and you are unsure what it means, especially if the result is significantly outside range, you have symptoms, or the abnormality relates to a potentially important area such as kidney function, liver function, blood count, thyroid function, blood sugar, calcium, potassium, inflammation markers or hormones.

The NHS explains that blood test results should be discussed by a GP, nurse or specialist where needed, and that you can contact your GP surgery or specialist if you do not understand your result or have questions. You can read more on the NHS blood tests page.

When contacting your GP, try to make it easy for them to help. Send or bring:

the full report, not just a screenshot of the abnormal result
the date and time the sample was taken
whether it was finger-prick or venous
whether you were fasting
the name of the provider and laboratory if shown
any sample quality comments
your symptoms and when they started
your current medicines and supplements
any previous blood results for comparison

Be aware that NHS GPs may not automatically act on private results in the same way as NHS-ordered tests, especially if the test was not clinically indicated or the result needs confirmation. They may advise repeating the test through the NHS, arranging further investigation, reviewing medication or booking a routine appointment.

Step 7: do not start or stop medicines based only on a private result

This is one of the most important safety points.

Do not start prescription-only medication, stop prescribed medication, change your dose or begin high-dose supplements based only on a private blood test result unless a qualified clinician has advised you to do so.

For example:

Do not start thyroid medication because one thyroid marker is borderline.
Do not stop a statin because cholesterol has improved; it may have improved because the medicine is working.
Do not take high-dose iron unless iron deficiency has been properly assessed.
Do not take high-dose vitamin D long term without appropriate guidance.
Do not change diabetes medication based on a one-off glucose result without advice.
Do not take testosterone, oestrogen, progesterone or fertility medication based only on a private hormone panel.

Supplements can also cause harm. Iron, vitamin D, vitamin B6, iodine, potassium, magnesium and herbal products can all be risky in the wrong dose or in the wrong person. Some can also interfere with blood tests or medicines.

Step 8: compare with previous results

A trend is often more useful than a single result.

If you have previous NHS or private blood test results, compare them with the new result. Ask:

Has this marker been abnormal before?
Is it improving, worsening or stable?
Has anything changed recently, such as medication, diet, illness or weight?
Was the same laboratory method used?
Are the units and reference ranges the same?

A stable mild abnormality may be managed differently from a sudden change. A gradually rising HbA1c, falling haemoglobin, worsening kidney function or rising liver enzymes may need more attention than a one-off borderline result.

Step 9: consider whether the test was appropriate in the first place

Not every private blood test is useful for every person. Some tests are very helpful when chosen carefully. Others can create confusion if taken without a clear reason.

Before acting on an abnormal result, ask why the test was done:

Was it to investigate symptoms?
Was it part of routine screening?
Was it recommended by a clinician?
Was it bought as a large “wellness panel”?
Was it a repeat test to monitor a known condition?
Was it a home test for convenience?

Large panels increase the chance of finding at least one result outside the reference range. That does not mean large panels are always bad, but they can create anxiety and follow-up work if the results are not interpreted properly.

A good test should answer a useful question. A good follow-up plan should explain what the result might mean, whether it needs repeating and what action is appropriate.

Common abnormal private blood test results and what they may mean

The following sections explain common abnormal private blood test findings. They are not a diagnosis, but they can help you understand the kind of follow-up that may be needed.

Abnormal cholesterol results

High cholesterol, LDL cholesterol or non-HDL cholesterol may increase the risk of heart disease and stroke over time. However, cholesterol results are not interpreted in isolation. Age, blood pressure, smoking, diabetes, kidney disease and family history all matter.

NICE guidance on cardiovascular disease risk assessment and lipid modification recommends assessing overall cardiovascular risk and using that risk to guide prevention and treatment decisions. You can read the guidance at NICE NG238.

If your cholesterol result is abnormal, see our full guide: Cholesterol Blood Test Results Explained.

Abnormal liver function tests

Raised liver enzymes can be caused by many things, including alcohol, fatty liver, medication, supplements, viral infections, gallbladder or bile duct problems, intense exercise and liver disease. Mild abnormalities are common, but very high results or jaundice need prompt assessment.

Read more here: Liver Function Test Results Explained.

Abnormal kidney blood tests

Creatinine and eGFR are used to assess kidney function. Abnormal results may be affected by dehydration, muscle mass, medicines, kidney disease or acute illness. A sudden change in kidney function is more concerning than a stable mild reduction that is already known.

Read more here: Kidney Blood Test Results Explained.

Abnormal thyroid results

Thyroid results can be tricky because TSH, free T4 and sometimes free T3 need to be interpreted together. Borderline results may need repeating, while clearly abnormal results may suggest an underactive or overactive thyroid.

Biotin supplements, pregnancy, recent illness and some medicines can affect thyroid results. Do not start thyroid treatment based only on a private test without clinical advice.

Read more here: Thyroid Blood Test Results Explained.

Abnormal full blood count

A full blood count can show anaemia, infection, inflammation, low platelets, high platelets or changes in white blood cells. Some abnormalities are mild and temporary. Others need prompt review, especially if you have symptoms such as breathlessness, chest pain, fainting, unexplained bruising, persistent fever, weight loss or night sweats.

Read more here: Full Blood Count Results Explained.

Low ferritin or iron results

Low ferritin can suggest low iron stores. This is common, especially in people with heavy periods, pregnancy, restricted diets or blood loss. However, the cause matters. In men and postmenopausal women, iron deficiency often needs investigation for possible bleeding from the gut.

High ferritin

High ferritin does not always mean too much iron. Ferritin can rise with inflammation, infection, liver disease, alcohol intake, metabolic syndrome and some inherited conditions. It needs interpretation alongside CRP, liver tests, transferrin saturation and your clinical history.

Low vitamin D

Low vitamin D is common in the UK, especially in autumn and winter, in people who spend little time outdoors, people with darker skin, people who cover most of their skin, and people with some medical conditions. It is usually managed with supplements, but the right dose depends on the level and personal circumstances.

Read more here: Vitamin D Blood Test Results Explained.

Abnormal B12 or folate

Low B12 or folate may contribute to anaemia, tiredness, mouth ulcers, pins and needles, memory problems or neurological symptoms. B12 deficiency can sometimes cause nerve symptoms even before anaemia appears. High levels may be due to supplements but can sometimes need interpretation in context.

Raised HbA1c or blood sugar

Raised HbA1c may suggest prediabetes or diabetes, depending on the level. It should be interpreted with symptoms, previous results and sometimes repeat testing. If you have symptoms of very high blood sugar, such as extreme thirst, frequent urination, weight loss, vomiting, drowsiness or confusion, seek urgent medical advice.

Read more here: HbA1c and Blood Sugar Results Explained.

Raised CRP or inflammation markers

CRP is a marker of inflammation. It can rise with infection, inflammatory conditions, injury and many other causes. A raised CRP does not tell you exactly where the problem is. It must be interpreted with symptoms and other results.

Abnormal hormone results

Hormone results are highly context-dependent. Testosterone, oestrogen, progesterone, LH, FSH, prolactin and cortisol can vary by time of day, menstrual cycle stage, age, medication, contraception, pregnancy, stress, sleep and illness.

If a private hormone result is abnormal, it often needs careful interpretation rather than immediate treatment. For testosterone specifically, see Testosterone Blood Test Results Explained.

When should you repeat the test?

Repeating a test can be helpful when:

the abnormality is mild or borderline
the result does not match your symptoms
there was a sample quality issue
the test was taken at the wrong time of day
you were ill when the sample was taken
you had recently exercised heavily or drunk alcohol
the result was from a finger-prick sample and is surprising
your clinician wants to confirm the result before treatment

However, repeating is not always the right first step. If the result is very abnormal or you have concerning symptoms, you may need medical advice before waiting for another test.

How long should you wait before repeating a blood test?

The timing depends on the marker and the clinical situation.

Some results may be repeated within days if they are important or possibly affected by a sample issue. Others may be repeated after a few weeks or months, especially if lifestyle changes, medication changes or recovery from illness are involved.

For example, cholesterol and HbA1c are often reassessed over a longer period, while potassium, kidney function or full blood count abnormalities may need quicker review depending on severity. Your GP or testing provider should advise on timing.

Should you upload private blood test results to your NHS record?

There is no single answer. If a private result is clinically important, it is usually worth sharing it with your GP. Whether it becomes part of your NHS record depends on local processes and clinical relevance.

If you want your GP to review the result, send the full report rather than only the abnormal marker. Include the provider, laboratory, sample date, collection method and any clinical comments.

Do not assume that buying a private test automatically creates an NHS follow-up pathway. If a result is abnormal, you still need to actively contact the appropriate service.

What if your GP does not act on the private result?

This can be frustrating, but there are several possible reasons. The GP may feel the test was not clinically indicated, the result may be borderline, the sample method may be unreliable, or the result may need repeating through an NHS pathway before action is taken.

If you are worried, ask clearly:

Does this result need repeating?
Is this result clinically significant?
Could my symptoms be related?
Do I need an appointment, or is written advice enough?
Are there symptoms that should make me seek urgent help?
Should I stop, start or change anything?

If you still feel your concerns have not been addressed, you can seek a second opinion, speak to the private provider’s clinician, consult a pharmacist where appropriate, or book a private GP appointment. If symptoms are urgent or worsening, use NHS 111 or emergency services as appropriate.

How to prepare for a GP appointment about private blood results

To get the most from the appointment, prepare a short summary. This helps the clinician focus on the important details.

You could write:

why you ordered the test
what symptoms you have, if any
how long symptoms have been present
which results were abnormal
whether the test was finger-prick or venous
whether you were fasting
what medicines and supplements you take
any relevant family history
what you are most worried about

Bring the full PDF report or printout. If you have previous blood results, bring those too.

What not to do after abnormal private blood test results

There are a few common mistakes that can make things worse.

Do not diagnose yourself from one marker

One abnormal marker rarely gives the full answer. Blood tests need context, patterns and sometimes repeat testing.

Do not ignore a result because you feel well

Some important conditions can be silent at first. High cholesterol, early diabetes, kidney disease, anaemia and thyroid problems may not cause obvious symptoms in the early stages.

Do not assume “borderline” means meaningless

Borderline results are often not urgent, but they may still be useful. They can show early risk, a trend or a reason to repeat testing.

Do not buy more and more tests without a plan

More testing can sometimes help, but it can also create confusion. If one test is abnormal, the next step should be guided by the result, your symptoms and clinical advice.

Do not rely only on online forums or social media

Other people’s results may look similar but have different causes. Advice from forums can be misleading, especially for hormones, thyroid results, iron, vitamins and inflammatory markers.

Do not delay urgent care

If you have severe symptoms, do not wait for a private provider to reply by email. Use urgent NHS services.

Private blood tests and health anxiety

Abnormal results can trigger a lot of anxiety. This is especially true when results arrive late at night, appear in red, or come with limited explanation.

If you feel anxious, try to separate two questions:

Is this result medically urgent?
What is the appropriate follow-up?

If it is not urgent, you still deserve a clear explanation. But you may not need to solve everything immediately. Save the report, write down your questions and arrange a sensible review.

It can also help to avoid repeatedly checking the result, searching worst-case scenarios or ordering multiple extra tests in panic. A calm, structured follow-up is usually safer and more useful.

How to choose private blood tests more safely in future

If you use private blood testing again, choose tests and providers carefully.

Look for:

a clear explanation of who the test is suitable for
transparent pricing
clear sample instructions
UKAS-accredited laboratory testing where appropriate
clinician review or access to follow-up advice
clear guidance on urgent results
easy access to the full report, including units and reference ranges
honest explanation of limitations

Be cautious with providers that overpromise, imply that huge panels are necessary for everyone, or recommend supplements and treatments based mainly on their own testing packages.

A practical action plan after an abnormal private blood test

If you are staring at an abnormal result now, here is a sensible order of action:

Check symptoms first. If you have severe or worrying symptoms, seek urgent medical advice.
Read the full report. Look at the number, units, reference range and provider comments.
Check sample issues. Look for haemolysis, clotting, insufficient sample or transport delay warnings.
Consider timing. Was the test fasting, morning, cycle-timed or taken when you were well?
Compare previous results. Trends matter.
Ask the provider for interpretation. Especially if clinician review was included.
Contact your GP if needed. Share the full report and explain symptoms or concerns.
Do not self-medicate. Avoid starting or stopping medicines without advice.
Repeat only when appropriate. A repeat test should answer a clear question.
Make a follow-up plan. Know whether you need lifestyle changes, monitoring, treatment or further investigation.

The bottom line

An abnormal private blood test result is not a diagnosis by itself. It is a piece of information. Sometimes it is a useful early warning. Sometimes it is a mild, temporary or expected finding. Sometimes it reflects a sample issue. Occasionally, it needs urgent medical attention.

The safest response is to avoid both extremes: do not panic, but do not ignore it. Check whether the result is urgent, read the full report, consider sample and timing issues, speak to the provider, and involve your GP or a qualified clinician when needed.

Private blood tests can be valuable when they are chosen carefully and interpreted properly. The result is only the beginning; what matters most is what you do next.

Frequently asked questions

Does an abnormal private blood test mean I am ill?

Not always. A result outside the reference range can be due to many things, including normal variation, recent illness, sample problems, medication, supplements, diet, alcohol, exercise or an early health issue. It needs interpretation in context.

Should I contact my GP after an abnormal private blood test?

Yes, if the result is significantly abnormal, you have symptoms, you are worried, or the result relates to an important area such as kidney function, liver function, full blood count, thyroid function, blood sugar, potassium, calcium or hormones. Send the full report if possible.

Will the NHS accept private blood test results?

Your GP may consider private results, but they may also repeat the test through the NHS before making decisions. This depends on the result, the sample method, the laboratory, your symptoms and whether the test was clinically appropriate.

What should I do if my private blood test result is marked red?

Read the full report and check whether the provider has described it as urgent. If you have severe symptoms or the result is very abnormal, seek medical advice promptly. If you feel well and the abnormality is mild, contact the provider or your GP for interpretation.

Can a private blood test be wrong?

Yes. Blood tests can be affected by sample collection, labelling, transport, timing, haemolysis, clotting, insufficient sample, recent food, exercise, alcohol, illness and medicines. This is why unexpected results are sometimes repeated.

Are finger-prick blood tests reliable?

Finger-prick tests can be useful, but they are more vulnerable to collection problems than venous blood tests. If a finger-prick result is surprising or clinically important, a venous repeat may be recommended.

What does “borderline” mean on a blood test?

Borderline usually means the result is close to the edge of the reference range. It may not be urgent, but it may still need monitoring, repeat testing or interpretation alongside symptoms and other results.

Should I repeat an abnormal private blood test?

Sometimes. Repeating can be useful if the result is mild, unexpected, affected by a sample issue, or taken at the wrong time. However, very abnormal results or abnormal results with worrying symptoms should be discussed with a clinician before waiting for a repeat.

How soon should I repeat an abnormal blood test?

It depends on the test and the severity. Some results may need repeating within days, while others may be repeated after weeks or months. Ask your GP or testing provider for advice based on the specific marker.

Should I stop taking supplements before repeating a blood test?

Ask a clinician or the testing provider. Some supplements can affect results. Biotin, for example, can interfere with some hormone and thyroid tests. Do not stop prescribed medicines unless a clinician tells you to.

Can alcohol affect private blood test results?

Yes. Alcohol can affect liver enzymes, triglycerides, inflammation, blood sugar and other markers. Heavy drinking before a test can make some results harder to interpret.

Can exercise affect blood test results?

Yes. Intense exercise can affect muscle enzymes, liver enzymes, inflammation markers and sometimes kidney-related markers. If you exercised heavily before a test, mention this when discussing the result.

What if my private provider says I need urgent care?

Follow their advice. If they tell you a result is urgent or critical, contact NHS 111, your GP urgently, an urgent treatment centre or 999 depending on the symptoms and severity.

Can I treat low vitamin D myself?

Vitamin D supplements are widely used, but the right dose depends on your level, health conditions and whether you are taking other medicines. Very high doses can be harmful. Ask a pharmacist, GP or clinician if you are unsure.

Can I take iron if my ferritin is low?

Low ferritin may suggest low iron stores, but the cause matters. Some people need investigation for blood loss or absorption problems. Do not take high-dose iron long term without proper advice.

What if my private hormone test is abnormal?

Hormone results often depend on timing, age, sex, menstrual cycle, contraception, pregnancy, sleep, stress and medication. Do not start hormone treatment based only on a private result. Ask for clinical interpretation.

What if my private blood test found high cholesterol?

High cholesterol should be interpreted with your overall cardiovascular risk, including age, blood pressure, smoking, diabetes, kidney disease and family history. You may need lifestyle changes, risk assessment, repeat testing or medication discussion.

Can private blood tests diagnose cancer?

Most routine private blood tests cannot diagnose cancer on their own. Some markers may raise concern or need follow-up, but diagnosis usually requires clinical assessment and specific investigations. Do not rely on blood tests alone to rule cancer in or out.

What should I send to my GP?

Send the full report, including the result values, units, reference ranges, sample date, collection method, provider details and any comments about sample quality. Also explain your symptoms and why you ordered the test.

What is the safest next step if I am unsure?

If you feel very unwell or have severe symptoms, seek urgent help. If you are well but worried, contact the private provider for interpretation and arrange GP review if the result is significant, unexplained or linked to symptoms.