Lyme Disease Testing

If you have an erythema migrans (EM) rash, there is no need for testing and treatment should be started straight away.

NICE Guideline summary of recommendations on tests for Lyme disease:

NICE Guideline for Lyme Disease

The initial test offered by the NHS is called an ELISA test which is usually performed at your local hospital laboratory and takes a few days or possibly a week to come back. It can produce false positive and false negative results.

If the ELISA test is positive or equivocal, the blood sample is usually sent to the National Reference Laboratory at Porton Down in England or the NHS Highland National Lyme Borreliosis Testing Laboratory at Raigmore Hospital in Scotland. The Western blot (sometimes called an Immunoblot) is then performed. This test may still miss cases for various reasons. It’s important to be aware that a negative result cannot rule out Lyme disease, especially as it can take up to 4-6 weeks after being infected by the bacteria for antibodies to develop, if at all. 

You can request printouts of both of these tests and it’s advisable to do so for your own records.


  • Tests for Lyme disease have limitations. Both false-positive and false-negative results can occur. Therefore a negative result cannot rule out Lyme disease.(See NICE Guideline for Lyme disease).
  • Most tests for Lyme disease assess for the presence of antibodies and that the accuracy of tests may be reduced if: testing is carried out too early (before antibodies have developed) or the person has reduced immunity, for example, people on immunosuppressant treatments, which might affect the development of antibodies.*
  • There is no test available that can indicate that the infection has been eradicated.

See the NICE Lyme disease guideline for more on NHS testing information.

Image of vials of blood

‘Laboratory tests for Lyme disease have significant limitations relating to the accuracy of the tests, the timing of tests, a lack of consistency in interpretation of test results and the expense and time associated with conducting tests’ (Brunton et al)

IgM and IgG responses in Lyme disease

Some doctors are unaware that Lyme disease can behave differently to other conditions in terms of antibody responses. In many situations, an IgM response represents acute infection whereas IgG represents past infection but this is not necessarily the case with Lyme disease.

There is evidence that the IgM and IgG responses in Lyme are unusual and that, in particular, the responses may be slow and unpredictable, and that IgM antibodies may be produced throughout infection, even in late disease.

This paper states: ‘Previous studies showed that the immune response to Borrelia burgdorferi appears to lack robust T-dependent B cell responses, as neither long-lived plasma cells nor memory B cells form for months after infection, and nonswitched IgM antibodies are produced continuously during this chronic disease.’

The NHS can also use Cerebrospinal fluid (CSF) testing if neurological Lyme is suspected to be affecting the central nervous system. This incorporates testing the CSF fluid (obtained by lumbar puncture) and a paired serum (blood) sample. A definite diagnosis is confirmed by the presence of a high level of certain white blood cells (predominantly lymphocytes) in the CSF and specific antibodies to borrelia (IgM and IgG) by comparison with the blood sample plus neurological symptoms. It also requires measurement of serum albumin, IgM and IgG levels in both the CSF and the serum. 

Private Labs 

In the UK, it is possible to pay for private Western Blot testing for Lyme disease using the same test kit as the NHS uses, without producing a positive ELISA result first. This may be useful if your GP cannot order a Western Blot directly for some reason. Both laboratories use the same testing facilities as the NHS located at RIPL, Porton Down and therefore the result should be accepted by NHS doctors.

  • County Pathology Limited
    You either need your GP to authorise a Western Blot test or a doctor at this private laboratory can authorise it for you for a fee of £25.
  • The Doctors Laboratory
    Your GP needs to write a letter to request this Western Blot test.

Some private laboratories argue that their testing is superior to the testing offered by the NHS but often, these tests have not been independently evaluated or validated in a way which would enable them to be accepted by NHS doctors. 

Alternative Medicine Testing

Some alternative practitioners offer treatment for Lyme disease and other tick-borne infections. If this route is explored, it’s worth checking if a practitioner is listed on the General Naturopathic Council website.

N.B. As things currently stand, tests cannot prove the absence of Lyme disease or when the bacteria has been eradicated following treatment. It’s always best to seek the advice of a medical practitioner with experience of Lyme disease as history, symptoms and signs need to be taken into account when considering diagnosis. At the moment, there is an over-reliance on blood test results which do not always reveal the full picture.