A disorder that causes breathing to repeatedly stop and start, sleep apnea causes dips in blood oxygen levels that lead to an increase in blood pressure and a higher risk of hypertension. Those who suffer from sleep apnea may snore loudly and feel tired after a full night’s sleep. If you think you may have sleep apnea, be sure to consult your doctor for treatment options. You can learn more about sleep apnea and what to do about it in this alive.com article.