The water pressure in my house suddenly decreased to not more than a trickle; this is in all areas of the house and the outside faucet. I have a well and my house is 16 yeard old. I have never had problems before.

Do u have a filter on system? If so change it , may be clogged with dirt.

Do u have a pressure gauge on system? If so what does it read when pump goes on and when it goes off.

How long does it take to go from pump on to pump off?

On the bladder tank there is an air valve on top. Press it and see if water comes out. Do not hold long as this will make u have to recharge tank. If water comes out, bladder is bad and tank needs to be replaced.

If u have a valve before filter, hook hose to it and check if pressure is OK. If no or bad pressure, your well could be running dry or the pump is going bad .

Chuck

Crea's advice to check the pressure gauge is great. I'm going to guess your pressure is very low (below 20#). If that is so, check and make sure the breaker is on (probably it is). If so, then pull the grey cover off your switch and see if the points are closed. If they are closed, then you will need to use a voltmeter to see if you are getting current to your pump.

One more note. If the pump is above ground, have you made sure it is holding prime?