Feel tired and sleepy all the day?

Fatigue and lethargy: Extremely common symptoms. I don't see a question to in what you wrote. You should check with the doctor if these symptoms are new or unusual or interfering with your life either at home or work. The possibilities are endless.

Many possibilities.: There are innumerable medical, nutritional and emotional conditions that include being tired as a symptom. These range from simple issues to those far more complex. A good checkup and blood testing would be a good starting point.