Two of the causes of dizziness when lying down are Benign Paroxysmal Positional Vertigo (BPPV) and having a viral ear infection, according to Patient and NHS. Both conditions come with other symptoms that allow doctors to determine whether they are the cause.
A patient suffering from BPPV may experience bouts of dizziness that last for 20 to 30 seconds when they lie down. In addition, they may experience these symptoms when rolling over in bed, sitting up or bending over. Other symptoms accompanying BPPV include experiencing nausea, symptoms that worsen when they tilt their head to one side, dizziness that is worse in the mornings and lightheadedness that continues for several hours following an attack of dizziness. Usually this condition is self-limiting, but may reoccur after a little while.
Sometimes viral ear infections cause dizziness as well as pain and headaches. Some patients may find that they experience a loss of hearing, fever, drainage of fluid from the ear and a poor appetite. As this condition is viral, antibiotics do not limit it. However, patients can take pain relievers, like Ibuprofen and acetaminophen, until the infection clears. Adults who experience ear pain with or without discharge should see a doctor as soon as possible.