Dizziness when lying down, also known as BPPV or benign paroxysmal positional vertigo, is a harmless condition that generally doesn't require medical attention, since it tends to go away on its own. However, if an individual experiences dizziness for more than a week, or the dizziness is accompanied by fever, headache, hearing loss or other severe symptoms, he should consult a doctor, as he may be suffering from a more serious medical condition, notes Mayo Clinic.
BPPV occurs when there are changes to the inner ear, the part of the ear that is responsible for hearing and balance. The inner ear maintains balance through what's called the vestibular system, or vestibular labyrinth, which is comprised of semicircular canals and a set of otolith organs containing crystals. The crystals help maintain balance by moving when a person stands up or moves his head. When inflammation or an infection dislodges the crystals and keeps them from moving, this causes the inner ear to send mixed signals to the brain, which results in vertigo and dizziness, explains WebMD.
BPPV has many causes. In older people, this condition is most commonly caused by degeneration of the vestibular system, notes Dizziness-and-Balance.com. In people under 50, the most common cause is a head injury. Viruses, such as vestibular neuritis and Meniere's disease, can also result in BPPV.