I feel extremely tired even after sleeping 10+...

When there is a loss of smell, a rise in temperature, shortness of breath, diarrhea, cough and a sore throat, it is necessary to isolate yourself at home and contact the competent medical authorities to rule out infection with Corona

What is the treatment of feeling tired despite sleeping more than 10 hours

the cause may be hypothyroidism which is treated by levothyroxine and the cause may be anaemia which is treated by ferrous sulfate and the cause may be the presence of severe infection in the body which is treated by antibiotics or antiviral drugs according to the cause and the cause may be chronic fatigue syndrome by antidepressants

How to diagnose  feeling tired despite sleeping more than 10 hours

you should have thyroid function tests done to exclude the presence of hypothyroidism and yu should has CBC done to exclude the presence of anaemia and infection in the body

what is the causes of feeling tired despite sleeping more than 10 hours

hypothyroidism
anaemia
chronic fatigue syndrome
infection in the body

what is the associating symptoms of feeling tired despite sleeping more than 10 hours

face and leg swelling and hair loss in hypothyroidism
high heart rate and pale skin in anaemia
in chronic fatigue syndrom there will be  difficulty in concentration and headache
in the presence of infection in the body there will be fever

advise

you should have the lab tests done and follow up with the physician to provide the treatment