Laboratory investigations: The following tests are usually recommended in Grave’s disease:

I. Thyroid Function test

  • Serum TSH level: TSH levels are decreased in Grave’s disease
  • Serum T4 level: Serum T4 is increased
  • Serum T3 level: Serum T3 is increased
  • Resin T3 uptake test: Resin T3 uptake is increased
  • Radioactive iodine uptake test: Radioactive iodine uptake is high

II. Blood test

  • TSH receptor antibody (TSH-R Ab) levels are usually high. This may be of value in diagnosing Grave’s disease if exophthalmos, goiter and pretibial myxedema are not present.
  • Antithyroglobulin or antimicrosomal antibodies are usuallyelevated in Grave’s disease.

III. CT scan or MRI (Magnetic Resonance Imaging) may be done to rule out other causes like eye tumors or other disorders. MRI is the imaging method of choice to visualize Grave’s ophthalmopathy affecting the extra-ocular muscles (eye muscles which moves the eyeball).