Ingrown hairs, due to improper shaving techniques, typically cause underarm bumps. After shaving, the cut hairs turn back toward the skin penetrating the top layer and causing irritation and inflammation. Preventing underarm bumps involves proper shaving preparation, technique and aftercare.

Prepare your underarms for shaving by showering or applying a warm, wet compress to the area for five to 10 minutes. This will soften the hairs and reduce pulling and friction during shaving.

Apply a thick layer of shaving cream or gel to your underarms. Leave the cream or gel in place for several minutes before shaving. This will further soften your hair and prepare your skin for shaving.

Use only a clean, sharp, single-blade razor, and avoid shaving over the same area multiple times. If your underarm bumps are prone to infection, try pouring rubbing alcohol over your razor before shaving to eliminate bacteria. Shave in the direction of hair growth and avoid pulling your skin taut.

Rinse your razor blade after every stroke to remove hair, dead skin cells and shaving cream. Reapply shaving cream as needed.

Splash your underarms with clean water after shaving and then apply a cool compress to soothe your skin and prevent inflammation.

Exfoliate the affected area twice each day with a washcloth to release ingrown hairs and improve underarm bumps. Remove individual hairs by sterilizing a needle with rubbing alcohol and using it to lift ingrown hair tips out of the skin.

Treat severe cases of underarm bumps with topical retinoids, corticosteroids or antibiotics. These medications can relieve itching, control inflammation and treat infection.

Try other methods of hair removal, such as electrolysis or laser hair removal, if improved shaving techniques fail to eliminate your underarm bumps.