Background: The adrenal gland makes the hormone aldosterone. This helps regulate blood pressure. An adrenal gland tumor that makes too much aldosterone can cause high blood pressure and low potassium. The cause of these tumors is unknown, but sometimes they are inherited.

Objective: To study the genes that may cause primary aldosteronism in Black individuals.

Eligibility: People ages 18-70 who: Are Black, African American, or of Caribbean descent And have difficult to control blood pressure or primary aldosteronism Relatives of people with primary aldosteronism

Design: Participants who are relatives of people with primary aldosteronism will have only 1 visit, with medical history and blood tests. Participants with primary aldosteronism or difficult to control blood pressure (suspected to possibly have primary aldosteronism) will be screened with a 1-2 hour visit. If they qualify, they will return for a hospital stay for 7-10 days. Tests may include: Medical history Physical exam Blood tests: Participants will have a small tube (IV catheter) inserted in a vein in the arm. They may drink a glucose-containing liquid or get a salt solution. If medically indicated, they may have invasive blood tests with a separate consent. Urine tests: Some require a high-salt diet for 3 days. Heart tests Scans: Participants lie in a machine that takes pictures of the body. A dye may be injected through a vein. Small hair sample taken from near the scalp. Kidney ultrasound Bone density scan: Participants lie on a table while a camera passes over the body. If the doctors feel it is medically necessary, they will offer participants treatment depending on their results. These treatments may cure the patient of their disease and may include: 1. Having one adrenal gland removed by the Endocrine surgeon under anesthesia. Patients will have follow-up visits 2-4 weeks after surgery. 2. Taking drugs to block the effects of aldosterone Participants may return about 1 year later to repeat testing....