Make an informed choice

Risks

Having a test done is a choice. On this page you can take your time to read what to expect — the pros and the cons, how reliable the result is, what can happen during the sample collection, and what to do if something comes back you weren't counting on. Read it before you order.

On this page

What a test does and doesn't do

A test is a snapshot. You see what's measurable in your body at that moment — not what was there yesterday or what will be there tomorrow. A test does not provide a diagnosis and does not replace your GP.

We send you the measured values along with the lab's reference range. What those values mean in your situation — given your age, complaints, medical history and lifestyle — is best discussed with your GP.

Pros and cons

A preventive check has pros and cons. Think carefully about whether the pros outweigh the cons for you before you order a test.

Pros

  • A favourable result can give you peace of mind.
  • You get information that helps you ask your GP a more focused question.
  • An illness or increased risk can be detected early so you can take action in time.
  • You decide for yourself when and which tests you do, no referral needed.
  • You can do it at home or at a collection point near you.
  • The result is yours — we don't share anything with third parties without your consent.

Cons

  • An abnormal result can lead to follow-up testing at your GP or specialist.
  • A follow-up test or treatment can itself carry risks or side effects.
  • You may worry unnecessarily about a result that later turns out not to matter.
  • You may find something you don't yet have a plan for — for example an increased risk for which there is no treatment.
  • We have no contracts with health insurers; the cost is usually for your own account.
  • When applying for new insurance or a mortgage, questions about your health may be harder to answer if an increased risk has been found.
  • No test is one hundred percent reliable. A test may indicate something that isn't there, or miss something that is.

How reliable is a test

It's good to know that no test is one hundred percent reliable. How good the result is depends on the type of test, the laboratory, your situation and the moment you test.

  • Is a test one hundred percent reliable?
    No. With every test there's a chance it shows something that isn't there, or misses something that is. How strong the scientific basis for a specific test is, you'll find on the product page under the 'Evidence' tab.
  • What does a false favourable or false abnormal result mean?
    A false abnormal result means the test indicates something is wrong when it isn't — you may worry unnecessarily. A false favourable result means the test shows nothing while there actually is something — you feel reassured while a follow-up is actually needed. In both cases a conversation with your GP is important to interpret the result in your context.
  • How do I know which test is more reliable than others?
    On every test page you'll find under 'Evidence' an evidence level (strong, moderate, limited or insufficient) and the sources we used. Tests with limited or insufficient evidence carry an attention notice. When in doubt: call your GP or check thuisarts.nl.
  • What quality requirements apply to the laboratories?
    We work with accredited Dutch diagnostic and hospital laboratories and the German Medlab Stein (part of Limbach Gruppe, ISO 15189). For specific at-home sample analyses (hair, saliva, faeces, swab) we work with RP Sanitas Humanus in Kamperland (ISO 9001 / LRQA). Which lab handles which test is shown on /laboratoria.

The sample collection

Which collection method belongs to a test depends on the test. Below you'll read per method what to expect and what to watch for.

  • Blood draw at a collection point (venous)

    A vein puncture with a thin needle is a safe routine procedure, but things can happen: a bruise or small haematoma at the puncture site that goes away within days, mild dizziness or fainting (let the phlebotomist know if you've had this before), or in rare cases a mild inflammation at the puncture point. Tips: drink water beforehand, eat something if allowed (for non-fasting tests), stay seated for five minutes after, and don't lift anything heavy with that arm for a few hours.

  • Fingerprick at home

    A fingerprick is a quick prick on the side of your fingertip with a sterile lancet. About nine in ten people get it on the first try; sometimes a second prick is needed. Don't squeeze your finger hard — that mixes red blood cells with tissue fluid (haemolysis) and makes the result unusable. Wash your hands with warm water before, that helps blood flow. Follow the kit instructions exactly. If it doesn't work or you're unsure: contact us for a replacement kit.

  • Collecting urine

    For most urine tests, first morning urine (urine that has been in your bladder for four to eight hours) is preferred. Wash your hands, clean the urethral opening, and collect midstream urine: let the first stream pass into the toilet, catch the middle in the container, and the rest into the toilet. Submit as soon as possible. Until then, refrigerate (max twenty-four hours).

  • Collecting saliva

    For saliva tests — especially hormone tests like cortisol — the rule is: thirty minutes before collection, no eating, drinking (except water), smoking, brushing teeth or taking medication. On the collection day, no liquorice, because liquorice contains glycyrrhizin which affects cortisol levels. Follow the timing instructions in the kit; for cortisol, for example, immediately after waking up.

  • Collecting faeces (stool)

    For faecal tests (microbiome, parasites, calprotectin): collect the stool in the supplied container or sheet — avoid mixing with urine or toilet water. Close the container properly. Store cool and dark, and submit ideally on the same day.

  • Hair analysis

    For analyses of minerals or heavy metals in hair: chemically treated hair (dyed, bleached, permed) is not suitable — it changes the mineral composition. Some care products containing selenium or zinc can affect the result. Important: the scientific basis for clinical decisions based on hair minerals is limited. On the product page under 'Evidence' you can read how strong the evidence for a specific hair test is.

  • Swab at home (self-collection)

    For self-collection swabs (for example vaginal screening or mycology): follow the kit instructions exactly for correct placement of the brush or swab. For tests where blood makes the sample unusable, don't collect during your menstrual period. The kit instructions specify this per test.

If the result is abnormal

An abnormal result doesn't automatically mean something serious is going on. It does mean it's wise to consult a doctor. We don't interpret your result by default — your GP does, in your context (complaints, age, medical history, lifestyle).

For some results we send a brief generic explanation along. For values far outside the reference range, or results that require quick action, we recommend contacting your GP or the GP out-of-hours service the same day.

Finding something unexpected (incidental findings)

Sometimes a test finds something you weren't specifically looking for — an elevated liver value during a general check-up, or a DNA result that's also relevant for relatives. We call this an incidental finding. We have a separate policy for this, with an opt-in moment in the order process.

Read our incidental findings policy

Privacy and storage

Your health data are special category personal data under the GDPR and we treat them as such. You receive results encrypted via Zivver. The laboratory keeps the source results in line with the legal retention period for medical data (twenty years in the Netherlands under the WGBO, similar in Germany). We don't share your data with third parties without your consent.

Read our privacy statement

Cost and reimbursement

You pay for the test yourself. We have no contracts with health insurers; these tests fall under self-chosen preventive checks that are usually not reimbursed by basic insurance. Some insurers reimburse via supplementary insurance — check your policy. Employers sometimes cover it through a health budget.

Not satisfied or have a complaint

If something goes wrong, we want to hear about it. We start with a conversation or email exchange. If we can't resolve it together, you can turn to our independent complaints officer (Quasir). If that doesn't lead to a solution either, you can submit your dispute to the Geschilleninstantie Zorggeschil (recognised disputes body).

View our complaints policy

Questions to ask yourself

Run through these questions briefly before you order a test. If you're unsure about one or more answers, discuss it with your GP first.

  • What concrete question do I want to answer with this test?
  • Do I know enough about the condition or risk factor to make sense of a result?
  • What will I do with a favourable result? And with an unfavourable one?
  • Am I willing to have follow-up testing at the GP if needed?
  • Do I know which risks or side effects a possible follow-up test or treatment might have?
  • Do I find the pros greater than the cons for me personally?

Independent information

We think it's important that besides our information you can also consult independent sources. The following organisations provide reliable and commercially independent information about preventive health checks.

Still have questions?

Wondering whether a test makes sense for you, or want to know more first? Get in touch or check our frequently asked questions.

Get in touchGo to FAQ