Hypothyroidism differential diagnosis

Hypothyroidism Main page
Patient Information
Overview
Classification Primary hypothyroidism Hashimoto's thyroiditis Secondary hypothyroidism Tertiary hypothyroidism
Differentiating different causes of hypothyroidism
Screening
Diagnosis
History and symptoms

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1],Farman Khan, MD, MRCP [2]

Differential Diagnosis

The differential diagnosis of hypothyroidism can be divided into two major groups based on laboratory tests and clinical symptoms.

Laboratory based differentials

The hallmark of hypothyroidism is high THS and this can be found in variety of other conditions in addition to hypothyroidism, which include the following.

• Recovery from nonthyroidal illness : Patients acutely sick with other illness may have transient elevations in their TSH levels. Usually their T3,T4 are normal or slightly low. In these patients TSH and free T4 should be checked four to six weeks after recovery. Few of these patients are found to have hypothyroidism when rechecked after their illness.

• Primary adrenal insufficiency.

• Resistance to TSH: This happens due to alterations in the TSH receptor. Serum free T4 and T3 concentrations are typically normal or low. Many of these patients are euthyroid, while others are hypothyroid. This type of hypothyroidism is difficult to distinguish from subclinical hypothyroidism. Family history may be important to help differentiation. Other family members with defect in the TSH receptor augments the diagnosis of resistance to TSH.

• Pituitary adenoma:

• TSH-secreting adenomas secrete active TSH in autonomous way. These patients have normal or high serum TSH levels and high total and free thyroxine (T4) and triiodothyronine (T3) concentrations.

Differential diagnosis based on symptomatology

1. Depression All patient with symptoms of depression should be screened for hypothyroidism.
2. Anemia
3. Alzheimer dementia
4. Confusion
5. Mental slowness
6. Hypothermia
7. Chronic fatigue syndrome
8. Constipation
9. Fibromyalgia