Conn's syndrome is a rare health problem that occurs when the adrenal glands make too much aldosterone. This problem is also known as primary hyperaldosteronism. Aldosterone is a hormone that controls salt and potassium levels in the blood. Too much leads to high blood pressure. Only 1 out of 100 or fewer of all cases of high blood pressure are caused by Conn's syndrome. It is more common in females than in males. It can happen at any age, but more often in people in their 30s and 40s. The adrenal glands control many processes in the body. Their job is to keep the body in balance by making various hormones that are critical for maintaining good health. These hormones do many important things. For example, they help regulate fluid and salt levels in the body that affect blood volume and blood pressure. They also help the body react to stress and change. They cause a faster heart rate and boost other systems that help you to react quickly with a burst of energy when needed. Problems in the cortex or the medulla, then, can result in high blood pressure.