TSH levels are suppressed in all of the following conditions except:

In the context of thyroid function and the regulation of TSH (Thyroid Stimulating Hormone) levels, it is essential to understand how various conditions affect thyroid hormone production and feedback mechanisms.

In Graves' disease, which is an autoimmune hyperthyroid condition, there is an overproduction of thyroid hormones (T3 and T4). This excess thyroid hormone leads to a suppression of TSH levels due to negative feedback on the pituitary gland.

Similarly, in an autonomous toxic nodule, which is a hyperfunctioning thyroid nodule, the overproduction of thyroid hormones also results in suppressed TSH levels. The autonomous nature of the nodule allows it to produce thyroid hormones independently of TSH stimulation.

Acute viral thyroiditis typically presents with inflammation of the thyroid gland, often leading to transient hyperthyroidism. This may also suppress TSH levels initially due to the release of preformed thyroid hormones from damaged tissues.

In contrast, subacute hypothyroidism is a condition where the thyroid is underactive and does not produce enough thyroid hormones. This underactivity would not suppress TSH levels; in fact, the opposite occurs. The pituitary gland responds to low levels of thyroid hormones by increasing TSH release to stimulate the thyroid gland for hormone