What Is Chronic Lyme Disease?

Defining chronic Lyme disease

Chronic Lyme disease is a relatively new medical condition that is not as easy to define as it may seem. So before we explain chronic Lyme disease, it’s important to first define Lyme disease.

Lyme disease is an infection most commonly caused by the bacteria Borrelia burgdorferi, via infected ticks. When ticks infected with the bacteria bite humans, they can transmit the infection. The classic early symptoms of the infection are a large, circular rash around the tick bite, fatigue, headaches, joint pain, and body aches. 

The infection is easily treated and cured with antibiotics. But even with timely treatment, between 10% and 20% of people will experience symptoms after the infection has been cured. This condition is called post-treatment Lyme disease syndrome, which is sometimes referred to as chronic Lyme disease. 

Even though people use these terms interchangeably, there is a subtle difference. Experts prefer the term “post-treatment Lyme disease syndrome,” for which there are established diagnostic criteria (more on this to come). The term “chronic Lyme” is more ambiguous and less clearly defined. For example, some people use it to refer to a collection of symptoms with no clear cause, including when there is no clear connection to Lyme disease infection. 

For the purposes of this article, “chronic Lyme disease” is synonymous with “post-treatment Lyme disease syndrome.” We are specifically not referring to:

• Unexplained symptoms with no clear connection to Lyme disease

• Late-stage or disseminated Lyme disease, which is a different condition that results when the infection has not been treated

Symptoms of chronic lyme disease

There is a wide variety of symptoms associated with chronic Lyme disease, and everyone experiences these symptoms a little differently. The most common symptoms of chronic Lyme disease include:

• Unexplainable, excessive fatigue

• Joint pain

• Muscle aches

• Difficulty concentrating

• Sleep disturbance

• Headaches

• Numbness or weakness in the arms or legs

Because the symptoms can sometimes be subtle or vague, it can be hard for some people to pinpoint or explain their symptoms. It is common for people with this condition to describe feeling tired all of the time or not quite like themselves.

What causes chronic Lyme disease?

Specialists have not yet figured out why some people develop chronic Lyme disease and others don’t. Research currently suggests that it is caused by ongoing activation of the body’s immune (defense) system, even after the infection is gone. In this way, it is similar to an autoimmune disease. The immune system is initially activated to fight the infection, but, even after the bacteria is gone, it can get confused and start to attack parts of our own bodies.

Diagnosing chronic Lyme disease

A diagnosis of chronic Lyme disease starts with confirming a history of Lyme disease infection. This is not as straightforward as it may seem. Lyme disease is diagnosed with a combination of symptoms (like the classic ‘bullseye’ rash that develops in some people), as well as blood tests to look for signs of the infection. The specific type of blood test varies by the suspected time of the initial tick bite and stage of the infection. These blood tests can sometimes be difficult to interpret and do not always differentiate between early and late stages of infection.

If someone has a history of suspected Lyme disease and completed the recommended antibiotics for the infection, there are established guidelines from the Infectious Diseases Society of America (IDSA) that help to determine if they may have chronic Lyme disease. 

The diagnosis is considered for people who have a confirmed history of Lyme disease infection and are experiencing the following symptoms: 

• Fatigue

• Pain in the muscle or joints

• Difficulty concentrating

These symptoms need to have started within 6 months of initial Lyme disease diagnosis. The symptoms should also be present (even if intermittent) for at least a 6-month time period.

The diagnosis of chronic Lyme is less likely for people who have:

• A diagnosis of fibromyalgia or chronic fatigue syndrome 

• A previous history of unexplained pains or fatigue that preceded Lyme disease

• Other conditions that may explain the person’s symptoms

If you think you may have chronic Lyme disease, don’t hesitate to discuss your questions and concerns with your provider. Given that the symptoms could be coming from many different causes, it is important to find a provider who understands you and will help you to find the correct diagnosis.

How long does chronic Lyme last?

Most people with chronic Lyme disease will improve over time. Research has shown that most symptoms resolve within 9 months. After 12 months, almost all people improve and no longer have any symptoms. But it is important to remember that everyone is different, and that some individuals may have symptoms that last longer. This is why it helps to have a trusted medical provider that will provide support along the way and monitor your recovery.

Treatment for chronic Lyme disease

While there is no specific treatment for chronic Lyme, there are options that may help improve symptoms given their success in treating similar conditions like fibromyalgia. Different treatments include:

• Physical therapy

• Yoga

• Acupuncture

• Tai chi

What about antibiotics? Some researchers have looked into whether longer courses of antibiotics are beneficial. At this time, there is not any convincing evidence that this treatment approach provides any long-term benefit. In addition, there are risks of continued antibiotic treatment, such as the development of other types of resistant infections, allergic reactions, and even blood clots associated with the IV catheter used to administer the antibiotics. 

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Written by:

Katie E. Golden, MD

Katie E. Golden, MD, is a board-certified emergency medicine physician and a medical editor at GoodRx.

Reviewed by:

Sophie Vergnaud, MD

Sophie Vergnaud, MD, is the Senior Medical Director for GoodRx Health. An experienced and dedicated pulmonologist and hospitalist, she spent a decade practicing and teaching clinical medicine at academic hospitals throughout London before transitioning to a career in health education and health technology.

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