When diagnosed early and treated correctly, Lyme disease is quickly cured and therefore has little impact on the lives of those affected. On the other hand, if the diagnosis is not made early and the disease progresses to a late stage, it can be disabling. However, even in the late stage of the disease, treatment usually results in the disappearance or improvement of symptoms.
Past or still active Lyme borreliosis does not confer protective immunity, so it is possible to be infected several times.
Some patients who have had (treated) Lyme disease suffer from a set of aspecific symptoms described as "post-treatment Lyme disease syndrome". The exact cause of this syndrome is not yet known. Most medical experts believe that the persistence of symptoms is more likely to be the result of residual damage to the tissues and immune system following the infection, rather than the persistence of the bacteria itself. The term "chronic Lyme disease" is ill-defined and should not be used since there is, to date, no evidence of infection that is resistant to well-conducted antibiotic treatment.