My tongue has been swollen for a week i started to get patches of yellow thick coating on my tongue. and the other patches is just flesh what is wrong?

Thrush: The most common cause of the symptoms you describe is thrush. This is a yeast infection that typically occurs after prolonged or frequent antibiotic use but can happen for a variety of reasons, such as in patients who's immune system is weak and diabetics. Visit an ENT doctor. The treatment is usually a medicated mouthwash.

Geographic tongue: Obviously without pictures it is difficult to make a diagnosis. First go see your dentist. It sounds more like a flare up of geographic tongue and possible hairy tongue.

See dentist: Please visit your dentist. It could be thrush, geographic tongue, or something else. If you do not get better within 10 days, please make an appointment for a clinical exam. Take care..

Hows your digestion?: This sounds like geographic tongue but i dont like the swelling or the color. Yellow coloration is usually a digestive problem possibly weakened gall bladder. I would get this looked at soon.