The signs and symptoms of Lyme disease vary and usually affect more than one system. The skin, joints and nervous system are affected most often.
Early signs and symptoms
These signs and symptoms may occur within a month after you've been infected:
- Rash. A small, red bump may appear at the site of the tick bite. This small bump is normal after a tick bite and doesn't indicate Lyme disease. However, over the next few days, the redness may expand forming a rash in a bull's-eye pattern, with a red outer ring surrounding a clear area. The rash, called 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
In some people, the rash may spread to other parts of the body and, several weeks to months after you've been infected, you may experience:
- Joint pain. You may develop bouts of severe joint pain and swelling. Your knees are especially likely to be affected, but the pain can shift from one joint to another.
- Neurological problems. Weeks, months or even years after you were infected, you may experience 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.
- Eye inflammation.
- Liver inflammation (hepatitis).
- Severe fatigue.
When to see a doctor
If you've been bitten by a tick and experience symptoms
Only a minority of deer tick bites leads to Lyme disease. The longer the tick remains attached to your skin, the greater your risk of getting the disease. If you think you've been bitten and experience signs and symptoms of Lyme disease — particularly if you live in an area where Lyme disease is prevalent — contact your doctor immediately. Treatment for Lyme disease is most effective if begun early.
See your doctor even if symptoms disappear
It's important to consult your doctor even if signs and symptoms disappear because 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.
In the United States, Lyme disease is caused by the bacterium Borrelia burgdorferi, which is carried primarily by deer ticks. The ticks are brown and when young, they're often no bigger than the head of a pin, which can make them nearly impossible to spot.
To contract Lyme disease, an infected deer tick must bite you. The bacteria enter your skin through the bite and eventually make their way into your bloodstream. In most cases, to transmit Lyme disease, a deer tick must be attached for 36 to 48 hours. If you find an attached tick that looks swollen, it may have fed long enough to transmit bacteria. Removing the tick as soon as possible may prevent infection.
Where you live or vacation can affect your chances of getting Lyme disease. So can your profession and the type of outdoor activities you enjoy. The most common risk factors for Lyme disease include:
- Spendingtime in wooded or grassy areas. In the United States, deer ticks are most prevalent in the Northeast and Midwest regions, which have heavily wooded areas where deer ticks thrive. Children who spend a lot of time outdoors in these regions are especially at risk. Adults with outdoor occupations are also at increased risk. In the first two stages of life, deer ticks in the United States feed on mice and other rodents, which are a prime reservoir for Lyme disease bacteria. Adult deer ticks feed primarily on white-tailed deer.
- Having exposed skin. Ticks attach easily to bare flesh. If you're in an area where ticks are common, protect yourself and your children by wearing long sleeves and long pants. Don't allow your pets to wander in tall weeds and grasses.
- Not removing ticks promptly or properly. Bacteria from a tick bite can enter your bloodstream only if the tick stays attached to your skin for 36 to 48 hours or longer. If you remove a tick within two days, your risk of acquiring Lyme disease is low.
Left untreated, Lyme disease can cause:
- Chronic joint inflammation (Lyme arthritis), particularly of the knee
- Neurological symptoms, such as facial palsy and neuropathy
- Cognitive defects, such as impaired memory
- Heart rhythm irregularities
The best way to prevent Lyme disease is to avoid areas where deer ticks live, especially wooded, bushy areas with long grass. You can decrease your risk of getting Lyme disease with some simple precautions:
- Wear long pants and long sleeves. When walking in wooded or grassy areas, wear shoes, long pants tucked into your socks, a long-sleeved shirt, a hat and gloves. Try to stick to trails and avoid walking through low bushes and long grass. Keep your dog on a leash.
- Use insect repellents. Apply an insect repellent with a 20 percent or higher concentration of DEET to your skin. Parents should apply to their children, avoiding their hands, eyes and mouth. Keep in mind that chemical repellents can be toxic, so follow directions carefully. Apply products with permethrin to clothing or buy pretreated clothing.
- Do your best to tick-proof your yard. Clear brush and leaves where ticks live. Keep woodpiles in sunny areas.
- Check yourself, your children and your pets for ticks. Be especially vigilant after spending time in wooded or grassy areas. Deer ticks are often no bigger than the head of a pin, so you may not discover them unless you search carefully. It's helpful to shower as soon as you come indoors. Ticks often remain on your skin for hours before attaching themselves. Showering and using a washcloth may be enough to remove any unattached ticks.
- Don't assume you're immune. Even if you've had Lyme disease before, you can get it again.
- Remove a tick as soon as possible with tweezers. Gently grasp the tick near its head or mouth. Don't squeeze or crush the tick, but pull carefully and steadily. Once you've removed the entire tick, dispose of it and apply antiseptic to the bite area.