SCDhealthhub

Crises usually occur spontaneously. The pain occur when sickled cells get stuck in a blood vessel, blocking the flow of blood. This is sometimes referred to as sickling.

Sickling may be triggered by conditions associated with low oxygen levels, increased blood acidity, or low blood volume.

Common sickle cell crisis triggers include:

• sudden change in temperature, which can make the blood vessels narrow

• very strenuous or excessive exercise, due to shortage of oxygen

• dehydration, due to low blood volume

• infections

• stress

• high altitudes, due to low oxygen concentrations in the air

• alcohol

• smoking

• pregnancy

• other medical conditions, such as diabetes

It’s not always possible to know exactly what caused a particular sickle cell crisis. Many times, there’s more than one cause.