Sleep

Lack of sleep along with stress increases cortisol production and its long-term increase suppresses immune function. Lack of sleep prevents the production of cytokines that regulate the immune system. Sleep is a basic human need that is related to overall health, and yet we are constantly sleeping less than we should.

The quality and length of sleep plays an absolutely crucial role in how we will feel during the day. If you do not know how to strengthen your immune system and overall health, definitely focus on sleep quality.