Hydrocortisone is a steroid medicine. When a person's immune system is overreacting, hydrocortisone can calm it. This can relieve pain, allergic reactions, itching, and inflammation.
Hydrocortisone is a synthetic version of cortisol, an important stress hormone made within the body. Some people's bodies do not make enough cortisol naturally. Hydrocortisone is a treatment for these people.

Hydrocortisone cream, lotions, and ointments can treat many skin conditions, including:
Hydrocortisone injections can treat joints that are swollen and painful. They are used for conditions like arthritis, bursitis, and tennis elbow. They can relieve pain for months, or even up to a year.
Hydrocortisone cream, spray, ointments, and suppositories (which are inserted into the rectum) can treat hemorrhoids.
The Mayo Clinic describes the many other uses of hydrocortisone:
Hydrocortisone provides relief for inflamed areas of the body. It [treats] inflammation (swelling), severe allergies, adrenal problems, arthritis, blood or bone marrow problems, eye or vision problems, lung or breathing problems ([like] asthma), lupus, skin conditions, and ulcerative colitis.