In order to learn about the triggering disease, blood work alone is not enough.
To be able to provide a reliable diagnosis, an ultrasound (sonography) and scintigraphy are required in addition to the blood work.

Generally, the Struma is in need of treatment because an enlargement of the thyroid could result in a compression of the trachea (narrowing of the wind-pipe) and surrounding vessels. Mostly the Struma is easily treated with iodine and/or thyroid hormones.
In some cases - usually in larger gloiters with nodules - a suppression scintigraphy is neccessary to ensure or eliminate certain forms of thyroid hyperfunction - the so-called thyroid autonomia. If this is caused by so-called hot nodules the therapy with iodine or thyroid hormones would be wrong, instead a therapy with radioactive iodine (RAI), operation or Echotherapy - also called HIFU / high intensity focused ultrasound - (this therapy can be performed in our practice) would be considered.
Before considering the treatment with Echotherapy, a series of additional tests need to be conducted, such as a MIBI scintigraphy to exclude malignancy.

Other forms of thyroid diseases are, for example, autoimmune diseases such as Graves' disease. In this clinical picture, the thyroid almost gets completely out of control, it's overactive, resulting in uncontrolled increased release of thyroid hormones into the blood stream. Patients often suffer from a severe hyperfunction and particularly need to be treated when developing heart problems (cardiac symptoms). Primarly, this is done with medication that "slows down" the thyroid (antithyroid) or - if this treatment fails - by removing the whole thyroid using radioactive iodine or operation.
Patients with this disease absolutely need to avoid products or medication (contrast medium) that contain iodine. Selenium has proven itself as a supportive agent to ease the course of disease.

Hashimoto's thyreoiditis is also a common cause for an hypofunction. This autoimmune disease is like the "sister" of Graves' disease and also an autoimmune disease. In this case, the body forms antibodies against the thyroid which slowly destroys itself. Iodine, too, unfavorably influences the course of this disease and needs to be avoided. Selenium has proven itself as supportive in this case as well and is recommended all over the world.
If you suffer from a thyroid disease, the probability of your children to be affected as well is most likly, as the disease is usually inherited. This is also particulary true of malignant diseases of the thyroid.
By the way, smokers are considerably more at risk to suffer from a thyroid dysfunction than non-smokers. The most likly form would be the nicotine induced transmigrating thyroiditis that reactively occurs due to the chronic irritation of the larynx caused by smoking, that usually results in a hypofunction of the thyroid due to loss of thyroid cells caused by inflammatory decomposition.

Once lost, thyroid cells cannot be replaced or recover from the disease. A once occuring hypofunction usually needs to be treated lifelong with thyroid hormone pills.