What is sleep apnea and how do CPAP machines help after it's revealed Biden uses a mask

The White House revealed on Wednesday that President Joe Biden has begun using a CPAP machine to deal with longstanding sleep apnea.

"Since 2008, the President has disclosed his history with sleep apnea in thorough medical reports. He used a CPAP machine last night, which is common for people with that history," deputy press secretary Andrew Bates said in a statement.

Here what the condition is and how it can be treated:

What is sleep apnea?

Sleep apnea is a sleep condition in which breathing suddenly stops and starts repeatedly while a person is sleeping.

There are two main types of sleep apnea. The first is obstructive sleep apnea (OSA), which is the most common form and occurs when throat muscles relax and block air flow to the lungs, according to the National Heart Lung and Blood Institute.

The second form, central sleep apnea (CSA), occurs when the brain doesn't properly send signals to the muscles that control breathing.

Other symptoms include frequent loud snoring and gasping for air during sleep. While awake, a person may notice symptoms including fatigue, dry mouth and headaches, waking up to urinate at night and sexual dysfunction or lower libido.

How is sleep apnea diagnosed?

If a person is believed to be suffering from sleep apnea, their health care provider may refer them to a sleep disorder center to run tests and monitor patients overnight.

One test, known as a nocturnal polysomnography, involves hooking a patient up to equipment that monitors heart, lung and brain activity; blood oxygen levels; breathing patterns; and arm and leg movements during sleep, according to the Mayo Clinic.

Home sleep tests can also be performed, which involve measuring a patient's heart rate, airflow, blood oxygen levels and breathing patterns during sleep but at home rather than at a clinic.

The American Medical Association estimates about 30 million people in the United States have sleep apnea, but only six million are diagnosed with the condition.

Is sleep apnea serious?

Millions of people may suffer from sleep apnea, making the condition seem harmless, but it can be serious.

Complications of OSA include heart issues, high blood pressure, type 2 diabetes or liver problems while CSA can lead to cardiovascular complications, the Mayo Clinic said.

Both types of sleep apnea can cause daytime drowsiness or tiredness, which can lead to trouble focusing or concentrating.

What is a CPAP machine?

A CPAP, or continuous positive airway pressure machine, is a common form of treatment for sleep apnea.

CPAP machines keep the airways open so people can receive oxygen while they're sleeping. They can not only improve sleep quality but reduce the risk of health issues including heart attack and stroke, according to the Cleveland Clinic.

Different types of masks are available including one that just covers the nostril area, one that covers the nose, and a full mask that covers the nose and mouth.