Overview

Lyme disease is an infection caused by the bacterium Borrelia burgdorferi, transmitted to humans through blacklegged tick bites.
Symptoms can appear days or weeks after being bitten and, if untreated, may progress from mild to severe, affecting multiple body systems.
Early diagnosis and treatment are crucial to prevent long-term complications.

 

Early Symptoms

The first signs of Lyme disease usually appear 3 to 30 days after a tick bite. Watch for the following early symptoms:

Erythema Migrans Rash

  • Appears in 70–80% of Lyme disease cases.

  • Typically shows up around 7 days after a bite.

  • Often looks like a bull’s-eye — a central spot with a surrounding ring — but can also appear as a uniformly discolored area.

  • The rash can expand up to 12 inches across.

  • It is usually not painful, swollen, or itchy, but may feel warm to the touch.

Note: A small rash that appears immediately after tick removal and does not spread is likely a reaction to tick saliva, not erythema migrans.

Flu-Like Symptoms

Early Lyme disease often resembles the flu, causing:

  • Fever

  • Chills

  • Fatigue

  • Muscle and joint pain

  • Swollen lymph nodes

  • Headache

 

Later Symptoms

If untreated, Lyme disease can spread to other parts of the body over weeks to months, leading to more serious symptoms, including:

  • Dizziness

  • Shortness of breath

  • New erythema migrans rashes

  • Persistent fatigue

  • Body aches

  • Brain fog (difficulty thinking clearly)

 

Long-Term Complications

Without treatment, Lyme disease can result in chronic or severe health issues:

Neurologic Lyme Disease

The infection can reach the brain and nervous system, causing:

  • Meningitis (brain and spinal cord inflammation)

  • Stiff neck

  • Severe headaches

  • Vision issues and light sensitivity

  • Facial palsy (drooping of one or both sides of the face)

  • Radiculoneuritis (nerve pain, numbness, or weakness in limbs)
     

Lyme Arthritis

  • Inflammation and swelling, often noticeable in large joints such as the knees.

  • Typically develops 1–3 months after infection.

  • Affected joints may feel warm and painful.
     

Lyme Carditis

  • The bacteria can impact the heart’s electrical system.

  • Symptoms include:

    • Lightheadedness

    • Breathing difficulties

    • Heart palpitations

    • Chest pain

    • Fainting

  • About 1% of Lyme disease cases develop Lyme carditis, typically within one to two months after a tick bite.

 

When To See a Healthcare Provider

Seek medical care if you:

  • Notice a rash resembling erythema migrans

  • Develop flu-like symptoms a few days or weeks after a potential tick bite

A healthcare provider will diagnose Lyme disease based on:

  • Blood tests

  • Possible exposure history

  • Your symptoms

If your initial test is negative but suspicion remains high, a repeat test may be advised after a few weeks.
Most Lyme disease infections respond well to 2–4 weeks of antibiotics.

 

A Quick Review

Lyme disease is a bacterial infection spread through the bite of an infected blacklegged tick.
Early signs often include a bull’s-eye rash, fever, chills, and muscle pain.
Without prompt treatment, Lyme disease can lead to complications like arthritis, heart issues, meningitis, nerve pain, and facial paralysis.
If you suspect you have been bitten by a tick and develop symptoms, contact a healthcare provider promptly for evaluation and possible treatment.