First off, we have Hashimoto's Thyroiditis, which is very like hypothyroidism in many ways. The common symptomatology is as follows usually:
Fatigue
Feeling of depression
Gaining weight
Can't handle cold
Feeling sleepy a lot
Hair that is dry or coarse
Constipation
Skin that is very dry
Crampy muscles
Cholesterol levels that keep going up
Inability to concentrate
Legs that are swollen
As your hypothyroidism goes on further, you may have eyes with puffiness, and a heart rate which is very slow. A decreased body temperature along with heart failure is all too common. Hypothyroidism can even go into a coma if not treated properly.
Hashimoto's thyroiditis is very treatable if it is treated promptly just by taking a thyroid replacement hormone.
Sometimes with Hashimoto's, people may have a hyperthyroid problem instead of hypothyroid. In this case scenario, it is then called hashitoxicosis. The symptoms then will show as:
Swelling of the thyroid gland. This is due to an inflammation. You'll have a tight feeling in the throat
You might notice that there is a lump in front of the neck. This is referred to in medical terms as a goiter.
Trouble swallowing is a frequent problem. This is because the thyroid is becoming too large.
Silent Thyroiditis
is another form of a thyroid problem that is not common as in other thyroid disorders. It is typical for the thyroid blood testing to indicate a level that is too high, and the uptake of radioactive iodine low. Most of these people have been young women in pregnancy.
Diabetes and thyroid problems are often connected. See the site.
Diagnosis
The most important tests to begin diagnosis of thyroid problems of any type are the T3 and T4 blood tests. Since these tests may show normalcy in earlier hypothyroidism, another test called TSH is performed. This is known as thyroid stimulating hormone. Your pituitary gland is the gland responsible for secretion of thyroid hormones. If hypothyroidism is present, the TSH test will indicate it showing an increase that is abnormal.
Below, is a video of a doctor talking about thyroid conditions and treatments and how thyroid problems are often missed.