Fibromuscular dysplasia (FMD) is a rare medical condition. Patients with FMD have abnormal cellular growth in the walls of their medium and large arteries. FMD is an angiopathy that affects medium-sized arteries predominantly in young women of childbearing age. Most cases of FMD affect the carotid and renal arteries. The carotid arteries are in the neck and connect the heart and the brain. The renal arteries are the blood vessels that carry blood from the aorta to the kidneys.
Among patients with identified FMD, renal involvement occurs in 60-75%, cerebrovascular involvement in 25-30%, visceral involvement in 9%, and arteries of the limbs in about 5%. FMD occurs in most other medium-to-large arteries as well, including the coronary arteries the pulmonary arteries and the aorta. The areas of narrowing and bulging occur next to each other and can cause the artery to narrow so much that organs that receive blood from the artery are damaged. Fibromuscular dysplasia can cause a number of complications, such as high blood pressure or tears of the artery (dissection), if left untreated. Fibromuscular dysplasia is most common in women between the ages of 40 of and 60, but the condition can also occur in children and the elderly.
As a result, it is felt that there may be a genetic cause. Other possible causes of FMD include abnormal development of the arteries that supply the vessel wall with blood, resulting in inadequate oxygen supply; the anatomic position or movement of the artery within the body, certain medications, and tobacco use. Patients with FMD experience a variety of symptoms that are largely dependent on the location of the affected arteries. However, many patients have no symptoms at all and are diagnosed when an imaging test of the arteries is performed for another reason.