What is Lyme disease?
Lyme disease is an infection caused by the bite of an
infected tick. The tick is so small that you may not notice
the tick or its bite. Many ticks do not carry Lyme disease.
Even if a tick is infected, it may not transfer the disease
to you. An infected tick that is attached for less than 36
hours is less likely to transmit infection. For these
reasons, most tick bites do not cause Lyme disease.
The disease often begins as a rash. If you don't get
treatment, the infection can cause serious nerve or heart
problems as well as a disabling type of arthritis (pain and
swelling in one or more joints caused by inflammation).
How does it occur?
Bacteria called Borrelia burgdorferi cause Lyme disease.
The disease is spread to human beings by the bite of a tiny
tick infected with the bacteria. These ticks are found in
vegetation and on animals in woodlands, grasslands, and
marshlands. Wild birds, mice, raccoons, and deer, as well as
cats, dogs, horses, and cows, can carry the infected ticks.
Ticks may climb on humans from leaf litter and low- lying
vegetation in wooded, brushy, or grassy areas. Ticks cannot
jump or fly.
People usually become infected during the summer, when
they are more likely to be exposed to ticks. Hikers,
campers, hunters, and people living in wooded or rural areas
have a higher risk for Lyme disease.
This infection has been found on all continents except
Antarctica. In the US the infection is more common in the
What are the symptoms?
Lyme disease is hard to diagnose because its symptoms can
vary greatly from person to person. The first symptoms may
not even be noticed.
Untreated Lyme disease may progress through these 3
Three to 32 days after a bite by an infected tick, a skin
rash, called a bull's-eye or target rash, occurs at the site
of your bite. The rash begins as a large red spot that may
be flat or bumpy. The area of the rash feels warm, but it is
not painful or itchy. The rash slowly expands after several
days, often in a circular pattern. The center usually
clears, creating what is called a bull's-eye rash. Sometimes
the rash may blister or scab in the center. The thigh,
groin, and armpit are common sites for the rash, but it can
Although most infected people develop a rash, you may not
have this symptom, or you may overlook it.
You may feel like you have the flu, with such symptoms
Less common symptoms of early Lyme disease are:
inflammation of the eye, making it red
in men, a swelling of the testicles.
Even if you don't get treatment, the early symptoms
usually improve or go away within several weeks. However,
fatigue, drowsiness, and sometimes vague muscle or joint
pain may last for months after the rash has gone.
Several weeks to several months after the first symptoms
appear, about 15% of infected people develop problems with
their nervous system. These problems may include:
Meningitis, which is inflammation of the covering of
the brain and spinal cord.
Encephalitis, which is inflammation of the brain.
Cranial neuritis, which is inflammation of the
cranial nerves. These nerves pass from the brain to
other parts of the body through openings in the skull.
Inflammation of these nerves can cause weakness or
paralysis of one or both sides of the face (Bell's
About 8% of infected people develop heart problems, such
as carditis (inflammation of the heart) and problems with
the rhythm of the heart.
During this second stage, you may have pain in your
joints, tendons, muscles, or bones, usually without joint
swelling. These symptoms usually disappear within a few
Within a few weeks to 2 years after the start of the
infection, about 60% of people develop arthritis, with joint
pain and swelling. The knee is the joint most often
In stage 3 you may have temporary bouts of arthritis or
you may feel the arthritis all the time. You may have
ongoing nervous system problems, but this is less likely.
Symptoms of nervous system problems during stage 3 may
How is it diagnosed?
Lyme disease can be hard to diagnose. Your health care
provider will ask about your symptoms and medical history.
He or she will examine you.
You may have a blood test for Lyme disease. Or you and
your provider may decide to start treatment without the
How is it treated?
Lyme disease is treated with antibiotics. Early treatment
can help prevent possible complications. The choice of
antibiotic may depend on such factors as the stage of the
disease and whether your joints are inflamed.
If you are in stages 2 or 3 of the disease, you may also
need other treatments. This is especially true if you have
infection or inflammation of the heart, central nervous
system, or joints.
Pregnant and nursing women:
If you are pregnant and have Lyme disease, you may pass
the disease to your baby. Although this happens rarely, you
should call your health care provider right away if you are
pregnant and have symptoms of Lyme disease. Also, if you are
a nursing mother and are bitten by a tick and develop
symptoms of infection, contact your provider for advice.
How long will the effects last?
While you have the disease the symptoms may occur in
cycles lasting a week or so.
In most cases the symptoms go away a few weeks or months
after antibiotic treatment, but sometimes the symptoms last
several years. For example, after treatment for stage 1 of
the disease, you may have minor recurrences of headaches,
muscle or joint pain, or fatigue, but eventually you should
If the disease is not diagnosed and treated, the symptoms
can last for several years, but they will gradually lessen.
Permanent problems caused by the disease depend on your
situation. Meningitis, which can strike in stage 2, can be
life threatening, but this is rare.
How can I take care of myself?
To help take care of yourself, follow the full course of
treatment prescribed by your health care provider. You need
to take all of your antibiotic therapy. Do not stop taking
antibiotics because you start to feel better or your
symptoms go away. If you have side effects from the
antibiotic, call your provider about possibly getting a
What can be done to help prevent Lyme disease?
To avoid getting Lyme disease follow these measures:
Be aware of the areas where ticks live. Do not walk,
camp, or hunt in the woods of tick-infested areas
In areas of thick underbrush, try to stay near the
center of trails.
When you are outdoors, wear long-sleeved shirts
tucked into your pants. Wear your pants tucked into your
socks or boot tops if possible. A hat may help, too.
Wearing light-colored clothing may make it easier to
spot the small tick before it reaches your skin and
Use approved tick repellents on exposed skin and
clothing. Don't use more than recommended in the
repellent directions. Don't put repellent on open wounds
or rashes. Wash the spray off your hands. Be careful
with children because the repellents can make them ill.
DEET is a very effective repellent, but adults should
use preparations with no more than 35% DEET, and
children should use repellents with no more than 10%
DEET. DEET should be washed off your body when you go
Treat household pets for ticks and fleas. Check pets
after they've been outdoors.
Brush off clothing and pets before entering the
After you have been outdoors, undress and check your
body for ticks. They usually crawl around for several
hours before biting. Check your clothes, too. Wash them
right away to remove any ticks.
Shower and shampoo after your outing.
Inspect any gear you have carried outdoors.
Remove an attached tick with tweezers by gripping
the tick as close to your skin as possible and gently
pulling it straight away from you until it releases its
hold. Don't twist the tick as you pull, and don't
squeeze its body. Thoroughly wash your hands and the
bite area and apply an antiseptic such as rubbing
If you spend much time hiking, you may want to
include a pair of tick tweezers in your first-aid kit.
The tweezers are available at many sporting goods
If you do get bitten, see your health care provider.
Also check for a rash and other symptoms for about 4
weeks after the bite.