Aldosterone is a hormone that mainly helps your body control blood pressure by managing salt, water, and potassium balance in your kidneys.

Quick Scoop

  • Aldosterone is made by the adrenal glands (small glands that sit on top of your kidneys).
  • It tells your kidneys to keep sodium and water in the body and to get rid of potassium in the urine.
  • By adjusting how much water and salt you keep, it helps control blood volume and blood pressure.
  • It also plays a role in maintaining the body’s acid–base balance (how acidic or alkaline your blood is).

How it works (simple version)

When your blood pressure or blood volume drops, or your potassium level goes up, your kidneys and hormones trigger the renin–angiotensin–aldosterone system (RAAS).

That system signals your adrenal glands to release aldosterone into the bloodstream.

Aldosterone then:

  1. Acts mainly on the late distal tubules and collecting ducts of kidney nephrons.
  1. Increases sodium channels and sodium–potassium pumps in kidney cells, so more sodium is pulled back into the blood.
  1. Causes water to follow that sodium, increasing blood volume.
  1. Increases excretion of potassium (and hydrogen ions), which affects potassium levels and blood pH.

Key effects of aldosterone

  • Increases sodium reabsorption : Less sodium is lost in urine; more stays in the bloodstream.
  • Increases water retention : Water follows sodium, so blood volume and blood pressure tend to rise.
  • Increases potassium excretion : More potassium is lost in urine, helping keep blood potassium in a safe range.
  • Influences acid–base balance : Promotes hydrogen ion excretion and affects bicarbonate and chloride handling, which can push the body toward a more alkaline state if aldosterone is high.

Why it matters for health

Too much aldosterone (as in primary aldosteronism) can cause:

  • High blood pressure that is often hard to control.
  • Low potassium (hypokalemia), which may cause muscle weakness, cramps, or abnormal heart rhythms.

Too little aldosterone (for example in Addison’s disease or adrenal failure) can cause:

  • Low blood pressure, dizziness, or fainting from low blood volume.
  • High potassium levels (hyperkalemia), which can be dangerous for the heart.

Both high and low aldosterone states are medically important today because resistant hypertension and electrolyte problems are common topics in clinical research and discussions as of the mid‑2020s.

TL;DR: Aldosterone is a mineralocorticoid hormone from the adrenal glands that makes your kidneys hold onto sodium and water and dump potassium, helping keep your blood pressure, fluid balance, and acid–base status in a healthy range.

Information gathered from public forums or data available on the internet and portrayed here.