Photo Credit pollen image by asb from Fotolia.com. Allergies are a common cause of hives since an allergic reaction can trigger the immune system response that results in trapped fluid beneath the skin. An allergic reaction can occur due to something you ingested or were exposed to through the air.hoto Credit pollen image by asb from Fotolia.com. Allergies are a common cause of hives since an allergic reaction can trigger the immune system response that results in trapped fluid beneath the skin. An allergic reaction can occur due to something you ingested or were exposed to through the air.
There are likely to be other possible causes, so ask your doctor about your symptoms. 1  Various causes of drowsiness or sleepiness include: 2  Sleep debt. 3  Not getting enough sleep. 4  Shift work. 5  Jet lag. 6  Boredom. 7  Fatigue-see various causes of fatigue. 8  Sleepiness-see various causes of sleepiness.
Excessive daytime sleepiness is also known as narcolepsy. The condition is often associated with: 1  Cataplexy -- a sudden loss of muscle tone and paralysis of voluntary muscles associated with a strong emotion.  Sleep paralysis -- immobility of the body that occurs in the transition from sleep to wakefulness.