i always feel tire and sad, what is it?

Not an expert, but it could be depression, which you really need to visit a doctor and get checked.  Or it could be the affects of Sleep Apnea.  I have had Sleep Apnea for 6 years, and those symptoms are exactly like mine.  Do you know if you snore loudly at night(due to breathing through your mouth), unknowingly gasp for breath during sleep.  If so, good chance it is SA.  Talk with your doctor about possibility of both.  SA can be dangerous.

Hi Priscilla:

I have to say, Ford8 has some excellent points. I would want to know, how old are you?  If you are a younger individual, it could be exhaustion, since our students are often over committed to not only school, but athletics and other activities that don't give them enough time to rest. Pile them these activities on each other and you are going to be very tired, lack energy and probably feel sad as well.

While it may be depression (and could be sleep apnea, but this is unusual in younger people who are an average weight) it could be many physical things that can only be ruled out by your physician. For instance, under-active thyroid (hypothyroid) can make us very tired and sad as well. Poor nutrition, too much caffeine, and lack of exercise can easily cause this problem. Also consider what PMS (now called PMDD) may be doing to you as well. Not every female suffers from it, but many do. Your gynecologist can determine if you have this.

Please talk with your doctor, and if you are diagnosed with depression, seek counseling, and perhaps medication.

Best of luck,

Dr. Diana Walcutt

*Dr. Walcutt is a Psychologist. Dr. Walcutt's answers are not intended to diagnose or treat any medical or mental disorder. Any information given in a post about medication is for educational purposes only, and primarily to aid you in having an informed discussion with your own Psychiatrist/Physician.