Fibromuscular dysplasia (FMD) is a condition where the walls of medium-sized arteries, most commonly those leading to the kidneys and brain, develop abnormal cell growth, causing them to narrow, widen (aneurysm), or even tear (dissection). This can reduce blood flow and potentially affect how organs function.
Understanding Fibromuscular Dysplasia
FMD isn't a single disease, but rather a group of conditions that affect artery walls. The most common type involves alternating areas of narrowing and widening, giving the artery a "string of beads" appearance on imaging tests.
Key Characteristics:
- Artery Involvement: Primarily affects medium-sized arteries, most often the renal arteries (leading to the kidneys) and the carotid and vertebral arteries (leading to the brain). Other arteries, such as those in the legs, abdomen, or heart, can also be affected.
- Cause: The exact cause of FMD is unknown, but research suggests a combination of genetic predisposition, hormonal factors, and environmental influences might play a role. It is not caused by atherosclerosis (plaque buildup).
- Symptoms: Many people with FMD have no symptoms. When symptoms do occur, they vary depending on the affected arteries. For example:
- Renal artery FMD: May cause high blood pressure, kidney dysfunction, or a bruit (abnormal sound heard with a stethoscope) over the kidney area.
- Carotid or vertebral artery FMD: May cause headaches, dizziness, pulsatile tinnitus (ringing in the ears), stroke, or transient ischemic attack (TIA).
- Diagnosis: Diagnosis typically involves imaging tests, such as:
- Duplex ultrasound: Uses sound waves to visualize blood flow.
- CT angiography (CTA): Uses X-rays and contrast dye to create detailed images of arteries.
- Magnetic resonance angiography (MRA): Uses magnetic fields and radio waves to create images of arteries.
- Angiography: An invasive procedure where a catheter is inserted into an artery, and contrast dye is injected to visualize the artery under X-ray.
- Treatment: Treatment aims to manage symptoms and prevent complications. Options may include:
- Medications: To control blood pressure, prevent blood clots, or manage pain.
- Angioplasty: A procedure where a balloon catheter is used to widen narrowed arteries.
- Surgery: In rare cases, surgery may be necessary to repair or bypass affected arteries.
Impact and Outlook
FMD is a chronic condition, but with proper diagnosis and management, most people can lead relatively normal lives. Regular follow-up with a healthcare provider is essential to monitor for complications and adjust treatment as needed.
