A recent survey found that more people are sleeping less than six hours a night, and sleep difficulties visit 75% of us at least a few nights per week. A short-lived bout of insomnia is generally nothing to worry about.

The bigger concern is chronic sleep loss, which can contribute to health problems such as weight gain, high blood pressure, and a decrease in the immune system’s power, reports the Harvard Women’s Health Watch.

While more research is needed to explore the links between chronic sleep loss and health, it’s safe to say that sleep is too important to shortchange. The Harvard Women’s Health Watch suggests six reasons to get enough sleep:

Safety: Sleep debt contributes to a greater tendency to fall asleep during the daytime. These lapses may cause falls and mistakes such as medical errors, air traffic mishaps, and road accidents.

Mood: Sleep loss may result in irritability, impatience, inability to concentrate, and moodiness. Too little sleep can also leave you too tired to do the things you like to do.

Learning and memory: Sleep helps the brain commit new information to memory through a process called memory consolidation. In studies, people who’d slept after learning a task did better on tests later.

Metabolism and weight: Chronic sleep deprivation may cause weight gain by affecting the way our bodies process and store carbohydrates, and by altering levels of hormones that affect our appetite.

Disease: Sleep deprivation alters immune function, including the activity of the body’s killer cells. Keeping up with sleep may also help fight cancer.

Cardiovascular health: Serious sleep disorders have been linked to hypertension, increased stress hormone levels, and irregular heartbeat.