Alyson Powell Key

Urticaria, also known as hives, is an outbreak of pale red bumps or welts on the skin that appear suddenly. The swelling that often comes with hives is called angioedema. Allergic reactions, chemicals in certain foods, insect stings, sunlight, and medications can cause hives. It's often impossible to find out exactly why hives have formed. Hives cause reddish welts on your skin, which may be harder to see on darker skin tones.

Ulcerative colitis (UC) is an unpredictable condition. Even when you do everything right by taking your medication as prescribed, keeping your doctor's appointments, and making lifestyle changes, symptoms may return without warning. These can be some of the lowest moments with UC. Just when you settle into remission and begin to feel better, resuming a normal routine, symptoms can suddenly return, bringing back the bleeding, urgency, and fatigue.

Bronchitis happens when the bronchial tubes, which carry air to the lungs, become inflamed and swollen. This causes a nagging cough and mucus. When you breathe, air makes its way to your bronchial tubes, which are in the lungs. Bronchitis causes inflammation of these tubes. (Photo Credit: iStock/Getty Images) There are two types of bronchitis: Acute bronchitis Also called a chest cold, this type is more common. Symptoms last a few weeks, but they don’t usually cause problems beyond that time.