TIngling in the feet can be caused by a variety of conditions. In general, it is important to rule out serious causes of the tingling--so I would strongly recommend that you see your primary care doctor
to evaluate this condition.
In general, the tingling sensation in your feet could represent a neuropathy--which is defined as damage to the nerve. Neuropathy can have many causes--the first thing to rule out is nerve impingement. For example, back problems
can pinch a nerve that causes numbness
or tingling in the legs. If you have back pain this could be related. Other common causes of nerve problems that should be ruled out are: diabetes (high blood sugar), nutritional problems (like low B12 levels), hypothyroidism (low thyroid hormone which can also cause fatigue and constipation), syphilis (a sexually transmitted disease) or Lyme disease (a tick-borne infection). Other more rare disease like amyloidosis can also cause this. In general these are rare but should be ruled out. Finally, primary nerve disorders like demyelinating polyneuropathy can cause these symptoms.
If this is a nerve problem -- testing can be done to see the extent of the damage. It is important to note that if any weakness or loss of sensation occurs that you must quickly seek medical attention. While hopefully not a serious condition, these should be ruled out. Also important, there are very good medicines to reduce nerve pain (such as gabapentin). I would recommend seeing your primary doctor for a thorough evaluation.