Adult onset of low testosterone can result from disease or damage to the hypothalamus, pituitary gland or testicles. Although testosterone levels drop gradually after age 40, a precipitous drop is not normal and can cause a variety of symptoms.
<h3>Symptoms</h3>
Symptoms of a testosterone deficiency in adult men may include:
<ul>
	<li>Reduced sex drive</li>
	<li>Erectile dysfunction (ED)</li>
	<li>Loss of body hair</li>
	<li>Decreased energy</li>
	<li>Osteoporosis (thinning bones)</li>
	<li>Weakness</li>
</ul>
<h3>Treatment</h3>
Testosterone replacement therapy. Usually administered through a topical gel or intramuscular injection.