The most common medical problems that are associated with increased yawning are sleep deprivation, insomnia, sleep apnea, narcolepsy, and many medicines that cause sleepiness.

Yawning excessively is a condition where a person yawns more often than normal. This condition is caused by various reasons, such as boredom, sleepiness, or stress. Excessive yawning can also be caused by an underlying medical condition, such as sleep apnea, anxiety, or depression.

For several years, the main theory was that yawning brings in more oxygen — mainly for your brain. More recently, researchers discarded this theory, as studies revealed that a controlled lack of oxygen doesn't result in more yawning than usual.

Yawning is a stereotyped physiological behavior that can represent a sign or symptom of several conditions, such as stroke, parakinesia brachialis oscitans, parkinsonism, Parkinson's disease and epilepsy.