No symptoms
Loss of calcium from bones due to increased blood calcium levels
Mild forms of the condition have relatively mild symptoms:
Vague symptoms
Weakness
Fatigue
Depression
Aches
Severe forms have other symptoms:
Loss of appetite
Nausea
Vomiting
Constipation
Abdominal pain
Excessive thirst
Excessive urination
Bone pain
Muscle aches
High blood pressure
Confusion
Emotional behavior
Impaired thinking
Impaired memory
Delirium
Stupor
Coma
Thinning bones
Risk of fractures
Hypercalcemia (elevated blood calcium levels)
Symptoms from underlying cause
Tiredness
Mood changes
Confusion
Kidney stones
Bone pain
Constipation
Note that Hyperparathyroidism symptoms usually refers to various symptoms known to a patient, but the phrase Hyperparathyroidism signs may refer to those signs only noticable by a doctor.
there is a wide range of symptoms and side effects.
A great source of reading on this question - would be parathyroid.com
Some here can also give first hand experience.