Can thyroid problems cause weightloss?

High thyroid can. Excess thyroid hormone, or hyperthyroidism can lead to many body changes, including increased metabolism/heat production, tremors, fast heart rate and diarrhea. These effects may then lead to the weight loss that is commonly seen in hyperthyroidism. Most common causes of hyperthyroidism are graves' disease, over-active thyroid nodule(s), subacute thyroiditis and excessive thyroid pill intake.