Feeling tired all the time is often, but not always, a gradually developing condition associated with aging.
As we get older our energy levels seem to lower with each passing year, thus causing us to frequently feel tired.
However, there are also a number of clinical conditions resulting in one's feeling tired all the time.
Feeling tired all time could indicate that you are suffering from Chronic Fatigue Syndrome (CFS).
Four or more of the following symptoms that last six months or longer could indicate CFS:

1. Impaired memory or concentration, difficulty maintaining mental focus
2. Post-exertional malaise, where physical or mental exertions bring on "extreme, prolonged exhaustion and sickness"
3. Unrefreshing sleep
4. Muscle myalgia (muscle pain)
5. Pain in multiple joints
6. Headaches of a new kind or greater severity
7. Sore throat, frequent or recurring
8. Tender lymph nodes (cervical or axillary)

Other common symptoms include:

• irritable bowel, abdominal pain, nausea, diarrhea or bloating
• chills and night sweats
• chest pain
• brain fog
• shortness of breath
• chronic cough
• visual disturbances (blurring, sensitivity to light, eye pain or dry eyes)
• allergies or sensitivities to foods, alcohol, odors, chemicals, medications or noise
• difficulty maintaining upright position (orthostatic instability, irregular heartbeat, dizziness, balance problems or fainting)
• psychological problems (depression, irritability, mood swings, anxiety, panic attacks)
• jaw pain
• weight loss or gain.
  

Whether feeling tired all the time is, for you, a clinical condition or simply the result of aging there are factors each have in common.
An exciting discovery has been made that addresses this factor both have in common.
You can learn more about it HERE.