**2. Clinical manifestations**

Hyperthyroidism can mimic other health problems, which can make it difficult to diagnose. It can also cause a wide variety of signs and symptoms like, Unintentional weight loss, palpitations, missed heartbeats, increased appetite, nervousness, anxiety and irritability, tremulousness, excess sweating, menstrual irregularity, heat intolerance, changes in bowel patterns especially more frequent bowel movements, goitre, easy fatigue, muscular weakness, insomnia, thinning of skin, hair loss. Elderly are either asymptomatic or may have palpitations, easy fatigue, etc.

Signs include tremors, warm handshake, fast tachycardia/arrhythmia, flushing over upper body, brisk reflexes, goitre and prominent eyes. Early diagnosis has become possible because of easy availability of blood investigations for thyroid.

Cause of patient's thyrotoxicosis can be guessed from presentation of patient and disease duration. Patients with hyperthyroidism have symptoms since months and dating back is usually difficult, patients of acute thyrotoxicosis due to thyroiditis usually date back their signs and symptoms. Many patients having mild thyrotoxicosis attribute their symptoms to day to day fatigue, stress, etc.

Easy access to blood tests of thyroid has made diagnosis of thyrotoxicosis easy. It is important to differentiate between thyrotoxicosis and hyperthyroidism before anti thyroid drugs are initiated.

Clinical manifestations involve multiple systems of the body as follows.

#### **2.1 Cardiovascular system**

Alterations in cardiovascular function are due to increased circulatory demand that result from the hyper metabolism, first, in heart rate, and with more severe disease, in stroke volume [5]. Widening of the pulse pressure results from the increase in systolic and decrease in diastolic pressure due to reduced peripheral resistance [6, 7].

#### **2.2 Protein, carbohydrate, and lipid metabolism**

Both synthesis and degradation rates of proteins are increased indicated by muscle wasting. Uncontrolled diabetes can be due to increased degradation rate of insulin. Lipolysis is predominantly observed [8].

#### **2.3 Sympathetic nervous system and catecholamines**

The improvement in cardiac function with β-blockade in patients with hyperthyroidism has led to the concept that there is increased sympathetic

**49**

*Hyperthyroidism*

these patients [9].

**2.4 Nervous system**

examination.

**2.5 Muscle**

**2.6 Eyes**

orbitopathy (GAO) [13].

**2.8 Respiratory system**

respiratory muscles.

**2.9 Alimentary system**

**2.10 Haematopoietic system**

in thyotoxicosis [15].

**2.7 Skin and hair**

*DOI: http://dx.doi.org/10.5772/intechopen.90314*

tone or increased cardiac sensitivity to the sympathetic nervous system in

Nervousness, emotional lability, and hyperkinesia are major symptoms.

Emotional lability mental disturbance may be severe; the patient shifts positions frequently, and movements are quick, jerky, exaggerated, and often purposeless. In children, inability to focus may lead to deterioration of school performance. A fine tremor of the hands, tongue, or lightly closed eyelids is observed on clinical

Generalised wasting associated with weight loss. The weakness is most prominent

As shown in **Figure 2**, proptosis, stare, lid lag, globe lag, dry eyes, photosensitivity, corneal ulceration, loss of vision (uncommon) are features of Graves associated

Excessive sweating. Palmar erythema may resemble "liver palms," and telangiectasia may be present. Hair loss may increase. The nails are often soft and friable. A characteristic but uncommon finding is Plummer's nails, or onycholy-

Dyspnoea is common in severe thyrotoxicosis, mainly from weakness of the

An increase in appetite is common but is inadequate to meet the increased caloric requirements. The frequency of bowel movements is increased and hepatic dysfunction occurs [14]. Hepatomegaly and jaundice can develop with severe, prolonged disease, and liver failure was a cause of death before the development of

The increase in erythropoiesis results from both a direct effect of thyroid hormones on the erythroid marrow and increased production of erythropoietin. Association of pernicious anaemia can be there in 3% of Graves of which 3% have auto-antibodies to intrinsic factor; accelerated clearance of the vitamin

K-dependent clotting factors. Therefore, the dosage of warfarin needs to be reduced

sis, typically involving the fourth and fifth fingers [11].

successful treatment for patients with Graves' disease.

in the proximal muscles of the limbs, myopathy is also a feature of disease which involves distal muscles, ocular myopathy may mimic myasthenia gravis. Periodic paralysis of the hypokalemic type may occur together with thyrotoxicosis [10–12]. tone or increased cardiac sensitivity to the sympathetic nervous system in these patients [9].
