The signs and symptoms of Lyme disease vary and usually appear in stages.
Early signs and symptoms
A small, red bump often appears at the site of a tick bite or tick removal and resolves over a few days. This is normal after a tick bite and does not indicate Lyme disease.
However, these signs and symptoms may occur within a month after you’ve been infected:
Rash. From 3 to 30 days after an infected tick bite, an expanding red area might appear that sometimes clears in the center, forming a bull’s-eye pattern. The rash (erythema migrans) expands slowly over days and can spread to 12 inches (30 centimeters) across. It is typically not itchy or painful.
Erythema migrans is one of the hallmarks of Lyme disease. Some people develop this rash at more than one place on their bodies.
Flu-like symptoms. Fever, chills, fatigue, body aches and a headache may accompany the rash.
Later signs and symptoms
If untreated, new signs and symptoms of Lyme infection might appear in the following weeks to months. These include:
Erythema migrans appearing in other areas of your body.
Joint pain. Bouts of severe joint pain and swelling are especially likely to affect your knees, but the pain can shift from one joint to another.
Neurological problems. Weeks, months or even years after infection, you might develop inflammation of the membranes surrounding your brain (meningitis), temporary paralysis of one side of your face (Bell’s palsy), numbness or weakness in your limbs, and impaired muscle movement.
Less common signs and symptoms
Several weeks after infection, some people develop:
Heart problems, such as an irregular heartbeat. Heart problems rarely last more than a few days or weeks.
Liver inflammation (hepatitis).
When to see a doctor
If you’ve been bitten by a tick and have symptoms
Only a minority of blacklegged tick bites leads to Lyme disease. The longer the tick remains attached to your skin, the greater your risk of getting the disease. Lyme infection is unlikely if the tick is attached for less than 36 to 48 hours.
If you think you’ve been bitten and have signs and symptoms of Lyme disease — particularly if you live in an area where Lyme disease is prevalent — contact your doctor. Treatment for Lyme disease is more effective if begun early.
See your doctor even if symptoms disappear
It’s important to consult your doctor even if signs and symptoms disappear — the absence of symptoms doesn’t mean the disease is gone. Left untreated, Lyme disease can spread to other parts of your body from several months to years after infection, causing arthritis and nervous system problems. Ticks also can transmit other illnesses, such as babesiosis and Colorado tick fever.