The earliest sign is usually a rash, but not everyone gets one

Lyme disease starts when a tick infected with Borrelia burgdorferi bacteria bites you. The first symptom often appears 3 to 30 days after the bite, though some people never develop symptoms at all. The most common early sign is a rash called erythema migrans — it typically starts as a red bump at the bite site and expands outward in a circular or oval pattern, sometimes with a clear center that looks like a target or bullseye. The rash can grow to 12 inches across or larger.

Not everyone infected with Lyme disease develops this rash. Studies suggest 20 to 30 percent of infected people never see one, which is why relying on the rash alone can miss the disease. The rash itself is not painful or itchy — it is simply a visible sign that the bacteria have entered your bloodstream.

If you find a tick on your body, remove it promptly with tweezers by grasping it close to the skin and pulling straight out. Dispose of it in alcohol or seal it in a bag. Watch the bite site over the next month for any rash or expanding red area. If you develop a rash or flu-like symptoms within a few weeks of a tick bite in a region where Lyme disease is common, contact your doctor.

Key Takeaways

  • The most recognizable early sign of Lyme disease is a circular or expanding rash that appears 3 to 30 days after a tick bite, though about one in four infected people never develop a rash.
  • Early flu-like symptoms — fever, chills, fatigue, headache, muscle aches, and joint pain — often accompany the rash or appear on their own.
  • A blood test can detect Lyme disease, but it may be negative in the first week or two of infection, so timing matters when you get tested.
  • Later-stage Lyme disease can cause joint swelling (especially in the knee), facial paralysis, heart rhythm problems, and neurological symptoms weeks or months after the initial infection.
  • If you suspect Lyme disease, see a doctor who can examine you and order tests; early treatment with antibiotics is most effective.

Early flu-like symptoms that develop alongside or without a rash

Within days or weeks of infection, many people develop symptoms that resemble the flu: fever, chills, fatigue, headache, muscle aches, and joint pain. These symptoms can appear with the rash or completely independently. Some people experience only these systemic symptoms and no rash at all, which is why Lyme disease is sometimes mistaken for a viral illness.

The fatigue in early Lyme disease is often described as profound — people report feeling exhausted despite adequate sleep. Joint and muscle pain may be widespread rather than localized to one area. These symptoms typically last days to weeks if untreated, though they may resolve on their own in some cases even without treatment. However, the bacteria can continue spreading through the body even after the initial symptoms fade.

Later symptoms that appear weeks or months after infection

If Lyme disease is not treated in its early stage, the infection can progress and cause symptoms in different parts of the body. The most common later manifestation is Lyme arthritis — swelling and pain in joints, particularly the knees. This can develop weeks to months after the initial infection and may come and go or become chronic.

Neurological symptoms can also emerge weeks after infection. These include facial paralysis (usually on one side of the face), numbness or tingling in the extremities, meningitis-like symptoms such as severe headache and stiff neck, and cognitive difficulties sometimes called "brain fog." Some people develop heart rhythm problems, including a slow heartbeat or irregular beats.

These later-stage symptoms develop because the bacteria have spread beyond the initial infection site. They are less common than early symptoms but more serious if left untreated. The longer the infection persists without treatment, the more likely these complications become.

How doctors test for Lyme disease

A doctor typically begins by asking about your symptoms, recent tick exposure, and whether you live in or have traveled to an area where Lyme disease is common. The geographic distribution matters: Lyme disease is most prevalent in the northeastern United States, the upper Midwest, and the Pacific Coast, though cases occur in other regions.

The standard test is a two-step blood test. The first step is an ELISA (enzyme-linked immunosorbent assay), which screens for antibodies your immune system produces in response to the bacteria. If the ELISA is positive or equivocal, the second step is a Western blot, which is more specific and confirms the diagnosis. This two-step approach reduces false positives.

Timing affects test accuracy. In the first week or two of infection, your body may not yet have produced enough antibodies to show up on a blood test, so a negative test early on does not rule out Lyme disease. If your symptoms strongly suggest Lyme disease but your early test is negative, your doctor may recommend retesting in a week or two, or may start treatment based on clinical symptoms alone.

When to see a doctor about possible Lyme disease

Contact your doctor if you develop a rash that expands over days, especially if it appears after a tick bite or outdoor exposure in a Lyme-endemic area. You should also see a doctor if you have flu-like symptoms — fever, fatigue, headache, muscle or joint pain — without an obvious cause, particularly if they follow a tick bite or time spent outdoors.

If you develop neurological symptoms such as facial paralysis, severe headache with stiff neck, or numbness and tingling weeks after a potential tick exposure, seek medical attention. Similarly, unexplained joint swelling or pain, especially in the knees, warrants evaluation if you have been in an area where Lyme disease occurs.

Early treatment with antibiotics — typically doxycycline, amoxicillin, or cefuroxime, depending on your age and other factors — is most effective at stopping the infection and preventing later complications. Treatment duration is usually 14 to 21 days for early-stage disease. Starting treatment early significantly reduces the risk of progression to later-stage Lyme disease.

Distinguishing Lyme disease from other tick-borne illnesses

Other infections transmitted by ticks in the same regions as Lyme disease can cause similar early symptoms. Anaplasmosis and ehrlichiosis, caused by different bacteria, produce fever, headache, muscle aches, and fatigue. Rocky Mountain spotted fever causes a rash, but it typically appears on the wrists and ankles first and spreads inward, unlike the expanding rash of Lyme disease.

Babesiosis, a parasitic infection, causes fever, fatigue, and hemolytic anemia. Powassan virus, transmitted by ticks, can cause neurological symptoms. Because multiple tick-borne illnesses can occur in the same geographic areas and sometimes in the same person, your doctor may test for several infections at once if you have symptoms consistent with a tick-borne illness.

The key difference with Lyme disease is the characteristic expanding rash and the specific two-step blood test. If you are unsure whether your symptoms match Lyme disease, describe them to your doctor along with information about where you were when you may have been exposed to ticks. Your doctor can then determine which tests are appropriate.

What happens if Lyme disease goes undiagnosed

When Lyme disease is not treated in its early stage, the bacteria can spread throughout the body and cause persistent or recurrent symptoms. Some people develop chronic Lyme arthritis with ongoing joint pain and swelling. Others experience persistent neurological symptoms, including cognitive difficulties, peripheral neuropathy (nerve damage causing numbness or pain), or chronic pain syndromes.

The longer the infection persists, the more difficult it becomes to treat. Late-stage Lyme disease typically requires longer courses of antibiotics — sometimes intravenous antibiotics for neurological involvement — and recovery can be slower. Some symptoms may persist even after successful antibiotic treatment, though this is less common when treatment begins early.

This is why recognizing early symptoms and seeking prompt medical evaluation matters. Early diagnosis and treatment prevent progression and reduce the likelihood of long-term complications.

Frequently Asked Questions

Can you get Lyme disease from a tick bite that happened months ago?

Lyme disease symptoms typically appear within 3 to 30 days of infection. If you were bitten months ago and have only recently developed symptoms, those symptoms are unlikely to be from that old bite. However, if you were bitten months ago and the infection went untreated, later-stage symptoms such as arthritis or neurological problems can emerge weeks or months after the initial infection.

What if I removed a tick but did not see a rash — does that mean I do not have Lyme disease?

No. About 20 to 30 percent of people infected with Lyme disease never develop the characteristic rash. If you develop flu-like symptoms — fever, fatigue, headache, muscle aches — within weeks of a tick bite, those symptoms alone warrant a doctor's evaluation and testing, even without a rash.

How long does it take to get test results for Lyme disease?

A blood test can be processed within a few days to a week, depending on the laboratory. However, if your test is done very early in infection (within the first 7 to 10 days), it may be negative even if you are infected, because your body has not yet produced detectable antibodies. Your doctor may recommend retesting or starting treatment based on your symptoms.

Can Lyme disease be cured?

Early-stage Lyme disease is highly treatable with antibiotics, and most people recover completely with appropriate treatment. Late-stage Lyme disease also responds to antibiotics, though recovery may take longer and some symptoms may persist. The key is starting treatment as soon as possible after diagnosis.

Should I be tested for Lyme disease if I found a tick on me but have no symptoms?

Testing asymptomatic people after a tick bite is not routinely recommended, as most tick bites do not result in infection. Instead, monitor the bite site and your health over the next month. If you develop a rash or flu-like symptoms, contact your doctor. If you live in a high-risk area and are very concerned, discuss testing options with your doctor.