Gestational diabetes (GD or GDM) is a type of diabetes that develops exclusively in pregnancy when blood sugar levels get too high (hyperglycemia). It happens when the hormones from the placenta block your ability to use or make insulin. Insulin helps your body maintain the right amount of glucose in your blood. Too much glucose in your blood can lead to pregnancy complications. GD usually appears during the middle of …

Diabetes insipidus is a rare but treatable condition in which your body produces too much urine (pee) and isn’t able to properly retain water. Diabetes insipidus can be chronic (life-long) or temporary and mild or severe depending on the cause. Diabetes insipidus is mostly caused by an issue with a hormone called antidiuretic hormone (ADH, or vasopressin) — either your …

Diabetes is a condition that happens when your blood sugar (glucose) is too high. It develops when your pancreas doesn’t make enough insulin or any at all, or when your body isn’t responding to the effects of insulin properly. Diabetes affects people of all ages. Most forms of diabetes are chronic (lifelong), and all forms are manageable with medications and/or lifestyle changes. Glucose (sugar) …

Neuromyelitis optica (NMO) is a rare chronic condition that affects your eyesight and your ability to move. It’s an autoimmune disorder, meaning it happens because your immune system mistakenly attacks parts of your central nervous system. This condition has undergone name changes over the years. The condition’s original name, Devic’s disease, comes from Eugène Devic, the French neurologist who first …

A deviated septum is when the bone and cartilage that divides your nasal cavity is off-center. Your nasal septum separates the right and left sides of your nasal cavity. It’s why you have two nostrils. Up to 80% of the general population has nasal septum deviation. Some people don’t even realize they have a deviated septum because they don’t have …

Retinal detachment is a painless but serious eye condition. It happens when your retina, the layer of tissue at the back of your eye, detaches from the tissues that support it. A detached retina affects your vision and can lead to blindness. Your retina senses light and sends signals to your brain so you can see. When your retina pulls away from the tissues that support …

Desmoplastic small round cell tumor (DSRCT) is a rare type of soft tissue sarcoma. In DSRCT, fast-growing tumors develop in your peritoneum — the membrane that lines the inside of your abdomen and your pelvis. Anyone may develop DSRCT, but it typically affects men and people assigned male at birth (AMAB) between ages 20 and 30. Healthcare providers have treatments that can put …

Desmoid tumors are rare benign (noncancerous) tumors that develop in connective tissue — the network of tissue that supports and connects your bones, ligaments and muscles and keeps your organs in place. You can have a desmoid tumor anywhere in your body, but they typically affect your arms, legs or belly (abdomen). Other names for desmoid tumors are deep fibromatosis, aggressive fibromatosis or desmoid fibromatosis. Unlike cancerous …

Dermatomyositis is a rare disease that causes muscle weakness and rashes on your skin. It’s a form of myopathy. It can also cause severe symptoms that affect your ability to breathe and swallow. Dermatomyositis is a form of polymyositis that affects your skin in addition to your muscles. See your provider right away if you experience any symptoms of dermatomyositis. Some cases take …

Dermatographia is a common, benign (not harmful) skin condition. It causes you to develop raised marks (wheals) or a reaction similar to hives when you scratch your skin. Pressure or rubbing (friction) may also cause a reaction. Dermatographism, dermatographic urticaria and skin writing are other names for dermatographia. Who does dermatographia affect? Dermatographia can affect anyone. However, you may be more likely …