Lyme Disease (Tick Bites): Symptoms, Causes, Diagnosis & Treatment

Lyme disease is a common tick-borne illness caused by the bacterium Borrelia burgdorferi. It is primarily transmitted to humans through the bite of infected black-legged ticks. 

The disease can lead to both physical and mental symptoms, and it is crucial to be aware of its causes, diagnosis, and prevention methods in order to maintain good health.

Symptoms of Lyme disease may appear soon after infection or develop over time. 

These symptoms often include fever, fatigue, joint and muscle pain, swollen lymph nodes, and sometimes a characteristic bullseye-patterned rash.

Timely diagnosis and treatment are essential for a full recovery, as untreated Lyme disease can have long-lasting and severe effects on the body. Joints, muscles and skin may all be affected. 


Lyme disease presents a wide range of symptoms that can be categorized into three stages: Early Localized, Early Disseminated, and Late Disseminated.

Early Localized

During the early localized stage, symptoms usually begin within 3 to 30 days after the tick bite. One of the most common symptoms is a rash called erythema migrans.

This rash starts as a small red spot at the site of the tick bite and gradually expands, often resembling a bull’s-eye. Along with the rash, individuals may experience flu-like symptoms.

Early Disseminated

If Lyme disease is left untreated, symptoms may progress to the early disseminated stage within weeks to months after the tick bite. During this stage, the bacteria spread throughout the body. Some common symptoms include:

Muscle and Joint Pain

Patients often describe this pain as migratory, moving from joint to joint, commonly affecting the knees initially.

These pains may be intermittent and vary in intensity. 

Swollen Knees or Other Joints

This swelling may occur in one or more joints and typically involves large joints.

The inflamed joint may be painful and warm to touch, reduce mobility, and limit functionality. This symptom, known as Lyme arthritis, can arise and resolve spontaneously or can be persistent. 

Limb Weakness and Numbness

Patients may experience a decrease in strength or a peculiar sensation of pins and needles in their limbs.

These symptoms are due to the impact of Borrelia burgdorferi (the causative bacteria) on the nervous system. 

Neck Stiffness

In early disseminated Lyme disease, some individuals may experience neck stiffness. This symptom can be related to Lyme meningitis, a condition characterized by inflammation of the membranes surrounding the brain and spinal cord.

This can cause discomfort and may limit the range of head movement. Accompanying symptoms may include headaches and light sensitivity.

Lyme Carditis

Lyme carditis is a serious, though relatively rare, complication of early disseminated Lyme disease where the bacteria infects the heart tissue. This can interfere with the electricity flow through the heart, potentially causing irregular heart rhythms.

Symptoms might include light-headedness, fainting, shortness of breath, chest pain, and heart palpitations. 

Late Disseminated

The late disseminated stage can occur months to years after the initial tick bite if Lyme disease remains untreated. Symptoms during this stage can be severe and affect various parts of the body. Common symptoms at this stage include:

Neuropathy Symptoms

Patients may experience shooting pains, numbness or tingling in the hands or feet. This is due to the impact of the bacteria on the peripheral nervous system.

Such sensory disturbances can be distressing, may interfere with daily activities, and are typically a sign that the infection has progressed.

Severe Joint Pain and Swelling

In the late disseminated phase of Lyme disease, severe joint pain and swelling may occur. One or more joints may be affected, with the knees being most commonly involved. This condition is referred to as Lyme arthritis.

Lyme arthritis can be intermittent or persistent and could lead to cartilage and bone damage if left untreated. 

Muscle Pain

Patients may experience generalized muscle aches or localized muscle pain, often described as a deep, throbbing, or burning sensation.

Persistent muscle pain can interfere with daily activities and may impact quality of life. 

Sleep Disturbances

Sleep disturbances are common in individuals experiencing the late disseminated stage of Lyme disease. These disturbances may include trouble falling asleep, staying asleep, restless sleep, or not feeling refreshed even after adequate sleep.

These sleep issues can deteriorate the overall quality of life, causing daytime fatigue, cognitive issues, and mood changes. 

Cognitive Symptoms

Patients may encounter cognitive difficulties. These could involve trouble concentrating and short-term memory loss, sometimes referred to as “brain fog.”

This confusion can manifest as difficulty understanding, slowed thought-processing, or being easily bewildered.

These cognitive difficulties can impact a person’s ability to perform daily tasks and activities. 

Causes & Transmission

Lyme disease is an infectious disease caused by the bacteria Borrelia burgdorferi and, rarely, Borrelia mayonii. The primary vectors for transmitting Lyme disease are the black-legged tick (also known as the deer tick, Ixodes scapularis) and the western black-legged tick (Ixodes pacificus).

Ticks become carriers of the bacteria while feeding on infected animals like rodents, birds, and deer. They then transmit the bacteria while feeding on human blood. 

Not all ticks are infected, and the risk of Lyme disease transmission depends on the geographical area and the tick species.

The disease usually starts with a tick bite, after which the bacteria enter the bloodstream and begin to multiply. 

It is essential to note that the tick must be attached to its host for at least 36 hours to transmit the infection. Hence, early detection and removal can significantly reduce the risk of Lyme disease.

Risk Factors

Understanding risk factors is essential.

Spending time in wooded areas can increase your chances of coming into contact with deer ticks. These ticks are more common in areas with tall grass, shrubs, and piles of leaves.

Engaging in outdoor activities such as hiking, camping, or gardening in these environments makes you more vulnerable to tick bites.

Geographically, Lyme disease is most frequently reported in the Northeast, Upper Midwest, and Mid-Atlantic regions of the United States. Specifically, the northeastern United States has a higher prevalence of this infection due to its natural habitats, which are highly suitable for deer ticks. 

If you live or spend time in a high-risk area, it’s crucial to remain vigilant and take the necessary precautions.


Diagnosing Lyme disease can be challenging. However, early diagnosis is crucial in order to start the appropriate treatment and prevent long-term complications. A two-step testing process is recommended for Lyme disease using a blood sample.

Initial Lyme Disease Tests

The first step in diagnosing Lyme disease is the enzyme immunoassay (EIA) or immunofluorescence assay (IFA) test.

These tests measure the presence of antibodies in the blood that the body produces in response to the bacteria causing Lyme disease. If the first step is negative, no further testing is recommended. However, if it is positive or indeterminate, the second step is required to confirm the diagnosis.

Lyme Confirmatory Test

The second step is the Western blot test, which detects specific antibodies produced against different proteins of the bacteria. This test is performed to confirm a positive or indeterminate result from the first step. A positive result on both tests is considered evidence of Lyme disease.

It is important to note that these blood tests can sometimes produce false-negative results, especially in the early stages of the infection when the body has not yet produced enough antibodies. 

Therefore, healthcare providers should also consider the patient’s symptoms, exposure to tick-infested areas, and the possibility of other illnesses before making a diagnosis.

In some cases, additional tests such as polymerase chain reaction (PCR) or cerebrospinal fluid analysis may be performed to check for the presence of the bacteria in specific parts of the body.


Lyme disease is typically treated with antibiotics to target the bacteria. The choice of antibiotic depends on the stage and severity of the disease. 

In most cases, early-stage Lyme disease can be successfully treated with a two-week to four-week course of oral antibiotics.

For more severe cases, or when the infection has spread to the joints, nerves, or heart, intravenous antibiotics may be necessary. This treatment usually lasts for two to four weeks. 

Some patients with Lyme arthritis might also benefit from anti-inflammatory medications or pain relievers to manage symptoms.

If the Lyme disease progresses to an early disseminated stage, additional symptoms and complications may arise, such as neurological issues or joint swelling, with finger joints often affected.

In such cases, medical professionals might prescribe specific medications to address these symptoms, depending on the patient’s individual needs.

Complications of Lyme Disease

Complications can arise when the disease is untreated or not treated early enough. These complications can involve various bodily systems, including the joints, heart, and brain.

Lyme Arthritis

In the early disseminated stage of Lyme disease, symptoms may include tingling, muscle aches, and inflammation in the joints.

Some individuals might develop Lyme arthritis, a condition characterized by severe joint pain. It typically affects one or more large joints, such as the knee.

Lyme Meningitis

As the disease progresses to the late disseminated stage, more severe complications may arise. One such complication is meningitis, which is an inflammation of the membranes surrounding the brain and spinal cord.

If left untreated, Lyme meningitis can lead to encephalopathy, a dysfunction of the brain that can cause cognitive issues, memory problems, and difficulty concentrating.

Lyme Carditis

Another significant complication is the involvement of the heart. Lyme disease can cause cardiac issues, such as irregular heartbeat, leading to lightheadedness, shortness of breath, and chest pain.

This condition, known as Lyme carditis, occurs when the bacteria spread to the heart tissue, causing inflammation and damage.

Post-treatment Lyme Disease Syndrome

It’s important to note that approximately 10 to 20 percent of Lyme disease patients develop a condition known as post-treatment Lyme disease syndrome (PTLDS). PTLDS is characterized by lingering symptoms such as fatigue, joint pain, and cognitive difficulties even after completing antibiotic treatment.

While the exact cause of PTLDS is not yet fully understood, some researchers believe it could be due to residual bacterial fragments or an ongoing immune response triggered by the infection. 

There is currently no specific treatment for PTLDS. Given the very serious risks of undiagnosed, or late-diagnosed, Lyme disease, it is crucial to diagnose and treat the disease in its early localized stage to limit the chance of serious complications. 


Preventing Lyme disease primarily involves minimizing your risk of exposure to deer ticks, which carry the bacteria that causes the infection. There are several practical steps you can take to reduce your risk.

Avoid walking through tall grass and bushes in wooded areas.

Stay on trails when hiking or walking in the woods.

Wear light-colored clothing to better spot ticks on your clothes.

Wearing clothes such as closed toe shoes, long sleeves and pants to cover skin from ticks. Tuck clothing to minimize potential access to tick bites.

Use insect repellent containing DEET to deter ticks from biting you.

Always perform thorough tick checks on your body after spending time outdoors.

Insect repellent is a crucial component of tick prevention. The Centers for Disease Control and Prevention (CDC) recommend using products containing at least 20% DEET on exposed skin and clothing.

For added protection, apply permethrin on clothing and camping gear, as it can kill ticks on contact.

Regular tick checks are essential after spending time outdoors, even if you have used protective measures. Examine your entire body for ticks, paying close attention to hidden areas like the hairline, underarms, and groin.

Don’t forget to check pets, as they can carry ticks into your home. Promptly removing ticks can help prevent the transmission of Lyme disease.

Reduce tick habitats in your yard by keeping grass mown short, removing leaf litter, and maintaining a buffer zone between wooded areas and your home. It’s also advisable to keep play areas, patios, and decks away from wooded areas where ticks may reside.

As Lyme disease risk factors include living in or traveling to areas with high tick populations or spending time outdoors in these areas, being aware of your surroundings and preparing accordingly can make all the difference in prevention.

Frequently Asked Questions

What are the common signs of Lyme disease?

Early signs of Lyme disease include a rash, known as erythema migrans, that starts as a small red spot at the site of the tick bite and expands over time. 

Other symptoms may resemble the flu, such as fever, headache, muscle and joint pain, and swollen lymph nodes.

How is Lyme disease diagnosed?

Diagnosing Lyme disease involves a combination of clinical evaluation and laboratory testing. The diagnosis is often based on the presence of the erythema migrans rash, history of potential exposure to infected ticks, and the appearance of other symptoms.

Blood tests may be used to confirm the infection, but they might not be fully reliable in the early stages of the disease.

What causes Lyme disease?

Lyme disease is caused by a bacteria called Borrelia burgdorferi. It is conveyed to humans via the bite of infected black-legged ticks (deer ticks).

It’s important to note that not all tick bites result in Lyme disease. The tick must be attached to the skin for 36 to 48 hours or more before the Lyme disease bacterium can be transmitted. 

What are the stages of Lyme disease?

Lyme disease advances in three stages based on the symptoms and time following the tick bite:

Early Localized Stage

The early localized stage of Lyme disease usually starts a week to a month after a tick bite.

This stage is characterized by the appearance of the erythema migrans rash and flu-like symptoms.

Early Disseminated Stage

If not diagnosed or treated in the early localized stage, Lyme disease can progress to the early disseminated stage within weeks to months. This occurs as the bacteria spread throughout the body.

During this stage, bacteria spread throughout the body, possibly affecting joints, the nervous system, even the heart.

Late Disseminated Stage

The late disseminated stage of Lyme disease, also known as late Lyme disease, can occur months to years after the initial tick bite.

At this stage, the symptoms can become more severe and persistent. Lyme disease can cause chronic joint inflammation, neurological problems, and other serious symptoms.

How can Lyme disease be prevented?

Preventing Lyme disease involves taking measures to avoid tick bites, such as using insect repellent, wearing long-sleeved shirts and trousers, and avoiding areas with tall grass and vegetation.

It’s also important to check your body for ticks after spending time outdoors and promptly remove any ticks you find.

What are the treatment options for Lyme disease?

Early-stage Lyme disease is typically treated with oral antibiotics for a period of 10 to a maximum of 21 days.

More advanced cases may require longer courses of antibiotics or intravenous (IV) treatment.