Antiphospholipid (AN-te-fos-fo-LIP-id) syndrome occurs when your immune system attacks some of the normal proteins in your blood. It can cause blood clots in your arteries or veins. And it can cause pregnancy complications, such as miscarriage and stillbirth. Blood clots in your leg veins cause a condition known as deep vein thrombosis (DVT). Damage from blood clots in your organs, such as your kidneys, lungs or brain, depends on the extent and location of the clot. For instance, a clot in your brain can cause a stroke. There's no cure for antiphospholipid syndrome, but medications can reduce your risk of blood clots.

Behcet's (beh-CHETS) disease, also called Behcet's syndrome, is a rare disorder that causes blood vessel inflammation throughout your body. The disease can lead to numerous signs and symptoms that may seem unrelated at first. They may include mouth sores, eye inflammation, skin rashes and lesions, and genital sores. The effects of Behcet's disease vary from person to person and may clear up on their own. Treatment involves medications to reduce the signs and symptoms of Behcet's disease and to prevent serious complications, such as blindness.