Trousseau's sign and chovstek's signs are positive in:
Hypoparathyroidism
When the parathyroid glands do not secrete sufficient PTH, the osteocytic resorption of exchangeable calcium decreases and the osteoclasts become almost totally inactive. As a result, calcium release from the bones is so depressed that the level of calcium in the body fluids decreases.
When the parathyroid glands are suddenly removed, the calcium level in the blood falls from the normal of 9.4 mg/dl to 6 to 7 mg/dl within 2 to 3 days and the blood phosphate concentration may double. When this low calcium level is reached, the usual signs of tetany develop. Among the muscles of the body especially sensitive to tetanic spasm are the laryngeal muscles.

Trousseau sign
	Trousseau sign is the spasm of the hand that is developed after 3 minutes of arresting the blood flow to lower arm and hand. The blood flow to lower arm and hand is arrested by inflating the blood pressure cuff 20 mm Hg above the patient’s systolic pressure.
Chvostek sign
	Chvostek sign is the twitch of the facial muscles, caused by a gentle tap over the facial nerve in front of the ear. It is due to the hyperirritability of facial nerve.

Reference: GUYTON AND HALL TEXTBOOK OF MEDICAL PHYSIOLOGY, THIRTEENTH EDITION(INTERNATIONAL EDITION ) page no 1014
Hyperparathyroidism
Hypothyroidism
Hypoparathyroidism
Hyperthyroidism