Does hyperglycemia cause weight gain?

Maybe yes, maybe no: Depending on a person's situation, hyperglycemia could lead to weight gain, or weight gain could lead to hyperglycemia, or hyperglycemia and weight gain could both be the result of some other medical problem. Since both symptoms can be from serious medical problems, a person should spend several visits at his doctor's office to figure out the problem (which could be diabetes).

Hyperglycemia: Usually not. Weight gain can cause hyperglycemia. Also, taking medication to control hyperglycemia can cause weight gain (especially insulin).