Dizziness and Headaches

• All three types of prescription sleep aides may cause dizziness, prolonged drowsiness, and headaches. Although these side effects may seem insignificant, it is important to inform your physician should you experience them. According to mayoclinic.com, your dosage or brand of pill may need to be switched.
  
  

Facial Swelling and Allergic Reaction

• Prescription pills that help you fall and stay asleep can cause facial swelling and allergic reactions. Anaphylaxis, a severe allergic reaction that causes the throat to close, may be triggered by these medications and is life-threatening. If you experience hives, swelling or difficulty breathing, seek medical attention immediately.
  
  

Sleep Behaviors

• Sleep behaviors are the most dangerous side effect of prescription sleeping pills. Some users have complained to their physicians about binge-eating and engaging in sexual activity while asleep. The medication has also contributed to sleep-driving reports. According to nytimes.com, the severity of sleep behaviors encouraged the Food and Drug Administration (FDA) to place warnings labels on 13 drugs.
  
  

Over-the-Counter Sleeping Pills

• Over-the-counter sleeping pills can be purchased by consumers over the age of 18 and can be taken by users age 12 and older. According to helpguide.org, the main ingredient in OTC sleeping pills is antihistamines. OTC medication can be used to treat insomnia for a few days; however, if sleeplessness continues, prescription medication may be required. Side effects of over-the-counter sleeping pills include constipation and dry mouth. Since this form of insomnia medication also causes drowsiness, dizziness and blurred vision, motor vehicles should not be operated after taking.
  
  

Warning

• Never mix alcohol with over-the-counter or prescription sleeping pills. In addition, avoid taking the medication if you do not have plans to go to sleep. Always give your doctor an accurate description of your insomnia problems to avoid an incorrect diagnosis. According to mayoclinic.com, sleeping pills may not be safe if you are pregnant or elderly.