Hemolytic crisis occurs from the rapid destruction of large numbers of red blood cells (hemolysis). The destruction occurs much faster than the body can compensate by producing more red blood cells.

A hemolytic crisis causes acute (and often severe) anemia, because the body cannot make enough red blood cells to replace those destroyed. The part of red blood cells that carries oxygen (hemoglobin) is released into the circulation, which can lead to kidney damage.

There are many causes of hemolysis, including:

• A lack of certain enzymes in red blood cells
• Autoimmune disease
• Certain infections
• Changes to the hemogloben molecules inside red blood cells
• Defects of the proteins that make up the internal framework of red blood cells
• Medication side effects
• Reactions to transfusions

Many of these conditions can lead to a hemolytic crisis.

If you have any of the following symptoms, contact your doctor:

• A decrease in the amount of urine you produce
• Fatigue, pale skin, or other symptoms of anemia, especially if these symptoms get worse
• Urine that looks red, red-brown, or brown (tea-colored)

Emergency treatment may be necessary. This may include a hospital stay, oxygen, blood transfusions, and other treatments.

When your condition is stable, your doctor will perform a physical examination and ask questions, such as:

• When did you first notice symptoms?
• What symptoms did you notice?
• Do you have a history of hemolytic anemia, G6PD deficiency, or a kidney disorder?

The physical examination may occasionally show swelling of the spleen (splenomegaly).

Tests may include:

• Blood chemistry panel
• Complete blood count (CBC)
• Coombs' test
• Kidney or abdominal CT scan
• Kidney or abdominal ultrasound
• Serum free hemoglobin
• Urine free hemoglobin

Schwartz RS. Autoimmune and intravascular hemolytic anemias. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 164.

Golan DE. Hemolytic anemias: red cell membranes and metabolic defects. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 165.