I Am Always Exhausted

Doesn't take much to make me tired put it that way .I will give you an example I walked from one end of town to another takes about 15 mins for me then had to walk to other side of town taking about 15 mins and by time got home was tired in all an hour walk tired me out .or other day did nearly full house clean about 3 hours and by 2 in afternoon I was completely tired nearly fell asleep but know I had to stay awake my son was coming home from school .but by 10 pm was flatlined.and just get tired very easily.