I also know of two people who were recently diagnosed with sleep apnea. They now use a c-pap machine and sleep fine. This is especially common for people who are significantly overweight. If you only have an extra 20 pounds, then that is probably not it.
Research the topic on the internet if you think this may apply to you. (sleep apnea)
You have to go to a sleep lab in a hospital for this to be diagnosed.
What causes people to wake up frequently is your airway closing then your body waking up to get a breath.