The signs and symptoms of sickle cell anemia vary. Some people have mild symptoms. Others have very severe symptoms and often are hospitalized for treatment.

Sickle cell anemia is present at birth, but many infants don't show any signs until after 4 months of age.

The most common signs and symptoms are linked to anemia and pain. Other signs and symptoms are linked to the disease's complications.

The most common symptom of anemia is fatigue (feeling tired or weak). Other signs and symptoms of anemia include:

• Shortness of breath
• Dizziness
• Headache
• Coldness in the hands and feet
• Pale skin
• Chest pain

Sudden pain throughout the body is a common symptom of sickle cell anemia. This pain is called a "sickle cell crisis." Sickle cell crises often affect the bones, lungs, abdomen, and joints.

A sickle cell crisis occurs when sickled red blood cells form clumps in the bloodstream. (Other cells also may play a role in this clumping process.) These clumps of cells block blood flow through the small blood vessels in the limbs and organs. This can cause pain and organ damage.

The pain from sickle cell crises can be acute or chronic, but acute pain is more common. Acute pain is sudden and can range from mild to very severe. The pain usually lasts from hours to a few days. Chronic pain often lasts for weeks to months. Chronic pain can be hard to bear and mentally draining. This pain may severely limit your daily activities.

Almost all people who have sickle cell anemia have painful crises at some point in their lives. Some have these crises less than once a year. Others may have 15 or more crises in a year.

Many factors can play a role in a sickle cell crisis. Often, more than one factor is involved and the exact cause isn't known. You can control some factors. For example, your risk for a sickle cell crisis increases if you're dehydrated (your body doesn't have enough fluid). Drinking plenty of fluids can lower your risk for a painful crisis. Other factors, such as an infection, you can't control.

Painful crises are the leading cause of emergency room visits and hospitalizations of people who have sickle cell anemia.