A severe rash. This is one of the most crucial indications that a patient has Lyme disease. The rash has a very distinctive shape, rather like a shooting target, and thus is easy to identify. The disease takes a time to incubate and is transferred through ticks, and the rash develops between three days to a month after a patient has been bitten. The average period before the rash shows up (and after the bite) is about a week. There will be no pain or any unpleasant itch at the site of the rash, but the area will feel warm, and the rash itself is extremely prominent.

Meningitis. Medically speaking, meningitis is an inflammation of the membrane that protects the brain, and this is, obviously, usually a fatal condition. This is a common symptom of Lyme disease, and in this case, the meningitis is, curiously enough, very mild. Most patients who develop meningitis as a symptom of Lyme disease can be treated as out-patients, that is to say, the symptom is mild enough to not make hospitalization mandatory. Standard symptoms of meningitis include a splitting headache, or pain around the areas of the back or the spinal column, and of the neck. A fever can also be a symptom, as can vomiting, or an inability to see clearly.

Issues with the brain and nervous system. Patients who have Lyme disease experience a curious psychological phenomenon in which they are convinced that their sickness is not severe. However, the disease can cause serious issues with the brain and nervous system. These include trouble with directing the mind and loss of memory. Patients also experience anxiety issues, emotional problems, personality disorders, and are often depressed. Issues with the nervous system, such as an extreme disruption in the awareness pattern and sensitivity of the basic senses, drooping shoulders or even a dysfunction of the cranial nerve, are quite common.