Bad tire, bent rim, warped rotors.....
Your power steering pump and or steering box may be about to give out on you.
Loose or worn steering parts, suspension worn, tires out of balance.
balance your tires
You need a steering stabalizer and if you have one it may need to be replaced.
Worn steering or suspension parts. This can be very dangerous, so have this repaired ASAP.
There are several causes of this but the most common we call a head shake. This is when the tires shake side to side, the cure is to insure the steering is tight and you add one or two hydraulic steering dampers.
Wheels are out of balance
Sounds like wheel balance, but check the steering dampner.
have front suspension checked
probably ball joints but could be a tire out of balance or a wheel bearing
You rotors are warped and will need replaced/resurfaced.
Tire out of balance, bent wheel, drive shaft bent, loose or worn steering parts.