Lyme disease is the most common illness caused by ticks and among the most feared-especially in Northeastern, North-Central and Pacific Coast states, where most cases occur.

But ticks that can cause lesser-known illnesses are found in virtually all parts of the US, and they are most active May through September in most regions.

You're at greater risk for all tick-borne illnesses if you live in areas populated by animals, including deer, that can carry ticks or if you spend a good amount of time outdoors-gardening, doing yard work or hiking, for example. In some cases, outdoor animals, such as dogs and horses, also can carry disease-causing ticks.

Important: If you are bitten by a tick and develop symptoms (such as fever, chills and muscle aches), see your primary care physician. If possible, save the tick to show to your doctor, who can send the tick to a laboratory to identify it.

Some tick-borne illnesses you should know about…


This disease occurs mainly in Northeastern, upper Midwestern and Northwestern states. The parasite that causes babesiosis is usually spread by the black-legged tick (commonly referred to as the deer tick), which also transmits Lyme disease. The disease tends to be most serious in older adults and people whose immune systems are compromised as a result of taking immunosuppressive drugs or undergoing cancer treatment. Life-threatening complications of babesiosis include kidney failure, liver problems and low blood pressure.

Main symptoms: Fever, fatigue and flu-like symptoms, Chills, in which the entire body shakes, may occur.

Diagnosis: Patients may have anemia or other blood abnormalities, which can be detected via routine laboratory tests. Diagnosis is usually based on examination of a blood smear to identify the presence of parasites.

Treatment: Mildly ill patients may require no treatment. Those with more serious symptoms often are given a combination of antibiotics, such as clindamycin (Cleocin) or azithromycin (Zithromax), plus an antiparasitic drug, such as atovaquone (Mepron).


This bacterial infection is transmitted primarily by the Lone Star tick in the Mid-Atlantic, South-Central and Southeastern US. Although some people experience serious illness, most get only a mild-to-moderate infection, while some are symptom-free. However, the disease can be fatal-most often in older adults or people with compromised immunity.

Main symptoms: Fever, headache, body aches, nausea and other flu-like symptoms.

Diagnosis: A special blood test can detect the bacterium that causes the disease. Some patients also will have low platelet and white blood cell counts and elevated levels of liver enzymes.

Treatment: A tetracycline antibiotic such as doxycycline (Vibramycin) taken for seven to 10 days.

Rocky Mountain Spotted Fever

First identified in the Rocky Mountain region, Rocky Mountain spotted fever (RMSF) has spread into other areas, including the Southeastern, Pacific and South Central regions of the US. RMSF, which is the most severe tick-borne illness, can be spread by the Rocky Mountain wood tick, the Lone Star tick and even the common dog tick. The mortality rate in untreated cases of RMSF is 20% to 25%—often due to myocarditis infection of the heart).

Main symptoms: Most often, patients have a fever and headache and also may develop a mottled rash that starts on the wrists, forearms or ankles and may spread to the palms of the hands or soles of the feet. Nausea, body aches and extreme fatigue also may occur.

Diagnosis: A blood test that detects the bacterium that causes RMSF.

Treatment: Doxycycline or another tetracycline antibiotic taken for one week to 10 days.

Important: Patients who develop the symptoms described above should seek treatment as quickly as possible.

Tick-Borne Relapsing Fever

Without treatment, this disease is fatal in about 5% to 10% of cases, usually due to liver failure and/or severe bleeding. Some patients die even with treatment. Fortunately, tick-borne relapsing fever (TBRF) is rare, with only about 25 cases reported in the US each year. TBRF is transmitted by a family of ticks known as soft ticks. Most cases occur in the Western US, particularly in people who have spent time in rustic cabins at high elevations, which tend to attract rodents that may carry soft ticks.

Caution: While most tick-borne infections occur when a tick has remained attached to a human for a day or more, patients can get infected with TBRF within one hour of a tick attaching to the skin.

Main symptoms: Sudden high fever with chills, body aches, headache and sweats. Within about three days, the patient's body temperature usually drops, but extreme sweats can occur. The fever typically recurs.

Diagnosis: There isn't a definitive test for TBRF. Characteristic symptoms include dehydration, an enlarged liver and spleen, and jaundice a yellowing of the skin).

Treatment: A tetracycline antibiotic taken for a week to 10 days.

Our Best Tick Tips

When spending time outdoors, consider using a tick repellent that contains 20% to 30% DEET on your skin and clothing. Check yourself and your pets) thoroughly for ticks after spending time in wooded and/or grassy areas.

Important: Some ticks are smaller than the head of a pin, so you must look very carefully. Use a magnifying glass, if necessary.

To remove a tick: Using pointed tweezers, grab the tick near its head and as close to your skin as possible, and pull it out. Don't use your bare hands. Remove as much of the tick as you can, being careful not to squeeze its body, which could introduce fluid from the tick into the skin. If any fragments remain in the skin, leave them there they will work themselves out. Such fragments do not increase risk for infection.

Teach Children How to Avoid Dog Bites

Children who experience dog bites and are the most seriously injured are under age seven. Teach children to avoid dog bites by showing them proper behavior and explaining basic rules: Never approach a dog you do not know or one that is alone, without an owner nearby. Ask the owner's permission before petting a dog. Do not go near a dog that is sleeping, eating, nursing puppies or playing with a bone or toy. Do not tease a dog in any way—the dog may not realize that you are being playful.

Want to Keep Reading?

Continue reading with a Health Confidential membership.

Sign up now Already have an account? Sign in