Lyme disease is a bacterial infection caused by Borrelia burgdorferi (and, rarely, B. mayonii) and spread through the bite of an infected blacklegged tick, also called the deer tick. It is the most commonly reported tick-borne illness in the United States and is concentrated in the Northeast, mid-Atlantic, and upper Midwest, with a smaller Pacific Coast focus. Importantly for our readers: Lyme disease is NOT transmitted by the Lone Star tick. Most people who are diagnosed and treated early recover fully with a standard course of antibiotics.
Last reviewed: 2026-07-20 · Educational only — not medical advice.
Not transmitted by the Lone Star tick. This illness is spread by Blacklegged tick (deer tick), Western blacklegged tick — a different tick. If a Lone Star tick bit you, this is generally not the concern.
What is lyme disease?
Lyme disease is an infection caused by the bacterium Borrelia burgdorferi (and rarely Borrelia mayonii) in the United States. It spreads to people through the bite of an infected blacklegged tick (Ixodes scapularis) in the eastern and central U.S., and the western blacklegged tick (Ixodes pacificus) along the Pacific Coast. According to the CDC, a tick generally must be attached for more than 24 hours before the Lyme bacterium can be transmitted, which is why finding and removing ticks promptly lowers risk. Lyme disease is a different illness from the conditions our readers most often ask about with the Lone Star tick: the Lone Star tick (Amblyomma americanum) does not transmit Lyme disease. A Lone Star tick bite can, however, produce a round, expanding rash that looks similar to Lyme's rash — a separate condition called Southern Tick-Associated Rash Illness (STARI). This page is educational and is not a substitute for professional medical advice, diagnosis, or treatment.
Symptoms
Erythema migrans (EM): an expanding red rash at the bite site, sometimes with a target or bull's-eye appearance, occurring in approximately 70-80% of people (CDC)
Fever and chills
Fatigue
Headache
Muscle and joint aches
Swollen lymph nodes
Later: arthritis with joint pain and swelling, especially in the knees
Later: facial palsy (drooping on one or both sides of the face)
Later: heart palpitations or an irregular heartbeat (Lyme carditis)
Later: shooting pains, numbness, or tingling in the hands or feet
How soon do symptoms appear?
The erythema migrans rash typically appears 3 to 30 days after the tick bite, with an average of about 7 days (CDC). Later signs such as arthritis, facial palsy, or Lyme carditis can develop days to months after an untreated infection.
Diagnosis
Doctors diagnose Lyme disease based on symptoms, physical findings such as the erythema migrans rash, and a history of possible tick exposure in an area where Lyme disease occurs. When laboratory testing is used, the CDC recommends a validated two-step antibody blood test. These antibody tests can be falsely negative during the first few weeks of infection, so a person with a classic erythema migrans rash and likely exposure is often treated promptly without waiting for test results. Testing is a clinical decision — a healthcare provider should interpret results in the context of your symptoms and exposure.
Treatment
Lyme disease is treated with antibiotics, and most people recover rapidly and completely when treatment starts early. For the erythema migrans stage in adults, oral antibiotics described by the CDC include doxycycline, amoxicillin, or cefuroxime axetil, with the shortest effective course generally preferred to limit side effects; the CDC lists azithromycin as a less-effective alternative for people who cannot take the first-line options. Specific medications, doses, and durations differ for children, during pregnancy, and for later-stage disease, and are decisions for a licensed clinician — this section is educational only and intentionally does not provide dosing. A small number of people report lingering fatigue, pain, or difficulty concentrating for months after treatment (sometimes called Post-Treatment Lyme Disease Syndrome); the cause is not fully understood, and studies have not shown a benefit from prolonged antibiotic courses.
Prevention
The best protection is avoiding tick bites. Use EPA-registered insect repellents (such as those containing DEET, picaridin, IR3535, or oil of lemon eucalyptus) on exposed skin, and treat clothing and gear with products containing 0.5% permethrin. Avoid wooded and brushy areas with high grass and leaf litter, and walk in the center of trails. After being outdoors, check your whole body for ticks (including the scalp, behind the ears and knees, armpits, and groin), shower within about two hours, and tumble dry clothing on high heat for at least 10 minutes to kill any ticks. If you find an attached tick, remove it promptly with clean, fine-tipped tweezers.
Where it occurs
Lyme disease in the U.S. is concentrated in the Northeast, mid-Atlantic, and upper Midwest, where the blacklegged tick (Ixodes scapularis) is established. A separate, smaller focus occurs along the Pacific Coast, where the western blacklegged tick (Ixodes pacificus) is the vector. Cases are much less common in the South and South-Central states, where the Lone Star tick predominates — and the Lone Star tick does not spread Lyme disease.
When to seek care: Contact a healthcare provider if you develop an expanding rash, fever, or flu-like symptoms within several weeks of a tick bite or time spent in an area where Lyme disease occurs, even if you never saw a tick. Seek care more urgently for signs of later disease such as facial drooping, severe headache with neck stiffness, or heart symptoms like palpitations, an irregular heartbeat, shortness of breath, chest pain, fainting, or dizziness, which can indicate Lyme carditis. When in doubt, call your provider — early evaluation and treatment give the best outcomes. For emergencies such as trouble breathing or anaphylaxis, call emergency services. Educational information only — not medical advice. See our sources and disclaimer.
Lyme Disease — frequently asked questions
Can a Lone Star tick give me Lyme disease?+
No. Lyme disease is spread by blacklegged (deer) ticks in the eastern and central U.S. and by western blacklegged ticks on the Pacific Coast — not by the Lone Star tick. A Lone Star tick bite can cause a round, expanding rash that resembles Lyme's rash, but that condition is called STARI (Southern Tick-Associated Rash Illness), which is a separate illness.
Does the rash always look like a bull's-eye?+
No. The erythema migrans rash appears in approximately 70-80% of people with Lyme disease (CDC), and it does not always form a classic bull's-eye. It can be a solid, expanding red patch, and some people never notice a rash at all, so other symptoms and exposure history matter too.
How long must a tick be attached to transmit Lyme disease?+
According to the CDC, in general a blacklegged tick must be attached for more than 24 hours before the Lyme disease bacterium can be transmitted (some other sources cite a longer window of roughly 36 to 48 hours). This is why checking for and promptly removing attached ticks lowers your risk. Ask a healthcare provider about your specific situation.
Will I have long-term problems after Lyme disease?+
Most people treated early recover completely. A minority report lingering fatigue, pain, or trouble concentrating for months afterward, sometimes called Post-Treatment Lyme Disease Syndrome. The cause isn't fully understood, and research has not shown that long courses of antibiotics help.
Can Lyme disease be prevented right after a tick bite?+
Removing an attached tick promptly and correctly is the most important step. In certain situations, a clinician may consider a single preventive dose of antibiotic depending on the tick type, how long it was attached, and local Lyme risk. This is a decision to discuss with a healthcare provider.
Step-by-step guidance for removing an attached tick.
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Lyme Disease
Lyme disease is a bacterial infection spread by blacklegged (deer) ticks — not the Lone Star tick. Learn the erythema migrans rash timeline, symptoms, testing, treatment, and prevention.
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