Lyme Disease Endometriosis and Fibroids: What to Know

September 13, 2025

Lyme Disease, Endometriosis, and Fibroids: What to Know

Pelvic pain, fatigue, and heavy periods can have many causes. If you or someone you love has been diagnosed with endometriosis or uterine fibroids—and also worries about Lyme disease—it’s natural to ask whether these conditions are linked. Here’s what current evidence says, how to tell similar symptoms apart, and the treatments most likely to help, based on guidance from trusted sources like the CDC, NIH, and ACOG.

Quick definitions

Lyme disease: A tick-borne infection caused by Borrelia burgdorferi in North America. Early symptoms can include an expanding “bull’s-eye” rash (erythema migrans), fever, chills, headache, fatigue, muscle and joint aches. Untreated infection can lead to neurologic, cardiac, or joint involvement. (CDC)
Endometriosis: Tissue similar to the lining of the uterus grows outside the uterus, causing inflammation, pelvic pain, and sometimes infertility. (ACOG/Office on Women’s Health)
Uterine fibroids: Benign growths of the uterine muscle that can cause heavy menstrual bleeding, pelvic pressure, and reproductive challenges. (Office on Women’s Health/ACOG)

Are Lyme disease, endometriosis, and fibroids connected?

There is no established causal link between Lyme disease and the development of endometriosis or uterine fibroids. Endometriosis is thought to arise from a combination of retrograde menstruation, immune and inflammatory responses, hormonal factors, and genetics. Fibroids are hormonally responsive benign tumors influenced by estrogen, progesterone, and genetic factors.

Some people report symptom flares of pelvic pain or fatigue around infections, and research has explored how immune dysregulation and inflammation can modulate pain pathways. But current peer‑reviewed evidence does not support the idea that Lyme disease causes endometriosis or fibroids, nor that antibiotics used for Lyme improve these gynecologic conditions. Major public health agencies do not list endometriosis or fibroids as complications of Lyme disease.

Overlapping symptoms—and how to tell them apart

Overlap can make things confusing. Here are common features of each condition:

Lyme disease: Erythema migrans rash (appears 3–30 days after a tick bite), fever, chills, headache, stiff neck, fatigue, muscle/joint pain. Later signs may include facial palsy, meningitis-like symptoms, heart rhythm issues, or migratory arthritis. Pelvic pain is not a typical hallmark.
Endometriosis: Cyclical pelvic pain, painful periods (dysmenorrhea), pain with sex, bowel or bladder pain especially around menses, possible infertility. Fatigue is common.
Fibroids: Heavy or prolonged menstrual bleeding (soaking through pads/tampons, passing clots), pelvic pressure/bloating, frequent urination, low back pain, anemia (fatigue, shortness of breath), reproductive issues depending on size/location.

If you have heavy bleeding, pelvic pressure, and anemia, fibroids are more likely. If your primary symptom is cyclical, debilitating pelvic pain and pain with sex or bowel movements, endometriosis is more likely. Flu-like symptoms, an expanding rash, or new neurologic signs after a tick exposure point toward Lyme disease.

How each is diagnosed

Lyme disease

Clinical diagnosis: The characteristic expanding rash in an endemic area is usually enough to start treatment without waiting for tests.
Laboratory testing: CDC recommends two-step serologic testing (an enzyme immunoassay followed by a second EIA or immunoblot for confirmation). Testing too early may be falsely negative; timing matters.

Endometriosis

Clinical assessment: History and pelvic exam; imaging helps rule out other causes. Many clinicians begin treatment based on symptoms.
Imaging: Transvaginal ultrasound can detect endometriomas; MRI helps map deep infiltrating disease.
Laparoscopy: Historically the gold standard for diagnosis and treatment; not always required before starting therapy.

Fibroids

Imaging: Pelvic ultrasound is first-line; MRI refines size, number, and location.
Evaluation: Assessment of bleeding, anemia, fertility goals, and pressure symptoms guides management choices.

Evidence-based treatment options

Lyme disease

Antibiotics: Early localized disease is typically treated with doxycycline for 10–14 days; amoxicillin or cefuroxime are alternatives (including during pregnancy, when doxycycline is avoided). Certain neurologic or cardiac complications may require IV ceftriaxone.
Post‑treatment symptoms: Some people have lingering fatigue or pain after appropriate therapy. Prolonged or repeated courses of antibiotics have not been shown to improve these symptoms and can be harmful. Both CDC and FDA caution against long-term antibiotic use for so‑called “chronic Lyme” due to risks like serious infections and C. difficile.

Endometriosis

First-line pain control: NSAIDs; heat; pelvic floor physical therapy.
Hormonal therapies: Combined oral contraceptives, progestin-only pills, depot medroxyprogesterone, levonorgestrel IUDs, and GnRH agonists/antagonists (with “add-back” therapy to mitigate side effects). Aromatase inhibitors may be used in select cases under specialist care.
Surgery: Laparoscopic excision/ablation of lesions; treatment of endometriomas; surgical planning tailored to pain and fertility goals.
Multidisciplinary care: Addressing pain pathways, mental health, and lifestyle can improve quality of life.

Fibroids

Manage bleeding/anemia: NSAIDs, tranexamic acid, and levonorgestrel IUDs reduce bleeding; iron supplementation for anemia.
Hormonal modulation: Combined OCPs, progestins, and GnRH agonists/antagonists can shrink fibroids temporarily and control bleeding (often used preoperatively or short-term).
Procedures: Myomectomy (fibroid removal), uterine artery embolization (UAE), radiofrequency ablation, MRI‑guided focused ultrasound, or hysterectomy. Choice depends on symptoms, size/location, and reproductive plans.

Fertility and pregnancy considerations

Endometriosis: Can impair fertility; options include medical optimization, conservative surgery, and assisted reproductive technologies.
Fibroids: Submucosal and cavity‑distorting fibroids can affect fertility and pregnancy outcomes; individualized planning is key.
Lyme disease: Treat promptly during pregnancy with pregnancy‑safe antibiotics. Doxycycline is generally avoided in pregnancy; amoxicillin is commonly used.

When to seek medical care

Immediately: Expanding bull’s‑eye rash; facial droop; severe headache or stiff neck; chest pain or palpitations; heavy bleeding soaking through ≥1 pad/hour for several hours; signs of severe anemia (fainting, shortness of breath at rest).
Promptly: Persistent pelvic pain, pain with sex or bowel movements, heavy or irregular bleeding, new pelvic pressure or urinary frequency, or fatigue interfering with daily life.

Prevention tips (tick bites)

Use EPA‑registered repellents (e.g., DEET, picaridin) and treat clothing with permethrin when in tick habitats.
Perform full‑body tick checks after outdoor activities; shower within two hours.
Remove attached ticks promptly with fine‑tipped tweezers.
Maintain yards by clearing brush and leaf litter; keep play areas away from wooded edges.

Bottom line

Current evidence does not show that Lyme disease causes endometriosis or fibroids. However, symptoms can overlap—especially fatigue and pain—and it’s possible to have more than one condition at the same time. Accurate diagnosis and evidence‑based treatment tailored to your goals (including fertility) offer the best outcomes. Work with your primary care clinician, a gynecologist, and—when appropriate—an infectious diseases specialist to build a plan you can trust.

Trusted sources and further reading

CDC: Lyme Disease overview, testing, and treatment — https://www.cdc.gov/lyme/
CDC: Two‑step (two‑tier) Lyme disease testing — testing guidance
NIH/NIAID: Lyme Disease — NIAID Lyme resource
CDC MMWR: Serious infections linked to prolonged antibiotics for “chronic Lyme” — MMWR report
ACOG: Endometriosis FAQ — https://www.acog.org/womens-health/faqs/endometriosis
U.S. Office on Women’s Health: Endometriosis — womenshealth.gov/endometriosis
U.S. Office on Women’s Health: Uterine Fibroids — womenshealth.gov/uterine-fibroids
ACOG: Uterine Fibroids FAQ — https://www.acog.org/womens-health/faqs/uterine-fibroids

This article is for educational purposes and is not a substitute for professional medical advice. Always consult your healthcare professional for diagnosis and treatment tailored to you.