This person has had a goiter since there teens, and when I looked up all the symptoms of hypothyroidism they had every one of them. They have had blood tests twice when they were younger. They all showed normal. But now they are not only over weight, tired all the time, have narcoleptic episodes, but they have started having trouble with short term memory and add and transposing numbers and letters. They are only 49 and don t get confused or any of the other signs of dementia. So they don t have dementia or Alzheimer s. They pass tests intellegance with a very high IQ as long as it don t include speed, I can think clearly just slow. My question is, if you simple blood tests come back normal could you still have hypothyroidism? Are there any other tests that should be taken?