A dizzy feeling associated with sitting or standing after a prolonged period of bed rest is called:

The sensation of dizziness that occurs when a person transitions from a seated or lying position to standing, particularly after a period of inactivity like bed rest, is known as postural hypotension. This condition is related to a sudden drop in blood pressure that can occur when standing up, leading to decreased blood flow to the brain, which causes the feeling of lightheadedness or dizziness.

Postural hypotension is commonly seen in individuals who have been lying down for extended periods or in the elderly, where the body's ability to regulate blood pressure effectively upon standing may be compromised. In contrast, the other terms mentioned refer to different conditions: vertigo is a sensation of spinning or dizziness, often associated with inner ear problems; decubitus seizures are not a recognized medical term; and decubitus ulcers are pressure sores that develop due to prolonged immobility, rather than being related to blood pressure changes. This distinction highlights why postural hypotension is the correct answer for the described symptoms.