The normal value for total testosterone in males is(NNN) NNN-NNNNng/dl for 35 years male. These values vary slightly with the different labs. The symptoms and signs of low testosterone are;
1) decreased muscle mass
2) low libido
3) erectile dysfunctions
Treatment is by the testosterone replacement which can be done either by the injection or by placing a patch or gel on the skin.
Please feel free for your follow up questions.