I constantly have thick snot in the back of mt throat. sometimes sound congested, but no other symptoms at all. what could be the problem?

Thick snot: You likely have allergies. Try irrigating the nose with saline spray. Make your own by mixing salt 1 tsp to one quart of water. Use a syringe or a bulb syringe to get 50 or more ccs of fluid and irrigate each nostril 4 to 5 times a day. Use a nasal steroid: nasal cort that is now available over the counter. 2 sprays each nostril once or twice a day. Good luck!