There are a number of factors that contribute to itchy skin at night. Some conditions may be intermittent, while others create chronic itching that interrupts sleep and affects the sufferer's overall quality of life. Severe chronic itchy skin at night could be a sign of a serious illness.
Liver
Cirrhosis of the liver creates bile byproducts that travel to the skin, creating extreme itching that becomes more noticeable at night.
Psoriasis
Psoriasis is an inflammation of the skin that can flare up at night following episodes of excessive drinking, stress or friction from rough bed covers.
Menopause
During menopause the skin becomes dehydrated and becomes itchier at night when fluids are not being consumed.
Allergies
Allergic reactions to chemicals in a mattress or bedding can cause itching at night. An allergy to fabric dryer sheets can be more pronounced when the body lies between sheets that were exposed to the fibres in the fabric softener for many hours.
Sun
Overexposure to the sun or tanning rays in a tanning booth can create irritating metabolites at the end of the day.
Heat
Taking a hot shower before bed can dry out the skin, so that by the middle of the night, the skin becomes so dried out that it creates intolerable itching.