I have sub-clinical hypothyroidism. Should I consider treatment?

I have had my thyroid hormone levels tested for the past 3 years. There has been a constant increase in the TSH level and slight decrease in T4 level. My TSH level is currently 6.34 while T3 and T4 are within the normal range. Hypothyroidism runs in my family. My father, sister and a paternal cousin have it. I have had excessive hair-loss, weight gain and signs of laziness for the past 3-4 years now. My doctor suggests therapy. Should I consider it? Thank you in advance for all those who care to answer.