Wondering if you have sleep apnea?  BMI is not a reliable screener by itself.  One of the effective screeners for sleep apnea is the STOP BANG questionnaire developed by the American Sleep Apnea Association.  There are 8 questions and one can screen one self.  
http://www.sleepapnea.org/assets/files/pdf/STOP-BANG%20Questionnaire.pdf  
Or http://www.westfieldhospital.com/uploads/STOP.BANG_1_.pdf  
Each one has a slight variance on the interpretation of the results.  

What are the risks associated with sleep apnea?  The obvious one is not having restorative sleep so there is excessive daytime sleepiness/tiredness/drowsiness.  The less obvious risks result in high blood pressure, stroke, heart attack, diabetes and GERD (gastric esophageal reflux).   Much of this is caused because of our lowered blood oxygen levels from our breathing being blocked by our tongue falling back obstructing our airway.  The body responds by pumping more blood at higher pressures to deliver what oxygen is available.  The GERD is caused from our abdominal and chest muscles straining hard to get the air down into our lungs and forces the acid from our stomach into the esophagus.  (The real docs out there can do a better job of explaining all of this.)

What to do next?  
A sleep study will determine whether you have sleep apnea or other related sleep disorders.  These can be done at home or in a sleep laboratory.  

If it is determined that you have sleep apnea, what are the treatment options?
Sleep docs place almost all patients on CPAP devices which forces air into nose and forces open the airway using an air pump and mask.  About 50% of the patients fail to use this after one year.
Another, less used treatment is the use of an oral appliance which is similar to a football mouth guard.  It is effective in treating about 90% of all sleep apnea patients and is a recommended treatment by the American Association of Sleep Medicine as first line treatment for mild and moderate sleep apnea and a secondary treatment choice after CPAP for severe apnea.  Most sleep doctors want you to fail on CPAP before going to the oral appliance although this is not what the guidelines say.  Most of the oral appliances advertised on TV have poor results based on our experience and putting the boiling hot appliance in the mouth really hurts.
Weight loss certainly helps with sleep apnea as well as all the comorbidities.
Surgeries (UPPP) and pillar implants have mixed results.  
Maxillary/Mandibular advancement surgeries also are effective and rarely done.  
Trach tubes work but is really a drastic solution.  (No one that I know does this.)

This is a chronic disease and you will be on lifelong treatment.  

Carl Cadwell
Former IVP