Which of the following is a symptom of a sickle cell crisis?

• A. Trouble breathing from lack of oxygen
• B. No symptoms at all
• C. Elevated stamina during activity
• D. Strong immunity to infection

Answer: (A)

A sickle cell crisis involves episodes where misshapen red blood cells block small vessels, cutting off oxygen delivery to tissues. When oxygen supply is reduced, breathing can become labored, leading to trouble breathing from lack of oxygen. This fits the acute changes seen during a crisis, where vaso-occlusion and hypoxia produce chest-related symptoms. Other options describe states not typical of a crisis: some people may have no symptoms between episodes, elevated stamina during activity isn’t characteristic of the pain and fatigue that accompany a crisis, and strong immunity to infection isn’t a symptom of a crisis (infection risk can be a separate concern, but not a symptom caused by the crisis itself).