The substances that roll off the assembly line in hormone glands also sometimes have unpronounceable names. Fortunately, this does not change their effectiveness.
- Thyroid hormones: thyroxine (T4), triiodothyronine (T3), calcitonin.
- Pancreatic hormones: insulin, glucagon.
- Adrenal hormones: adrenaline, cortisol, aldosterone, dopamine.
- Parathyroid hormones: parathormone
- Sex hormones, formed in testes, ovaries, adrenal glands: Androgens, (mainly testosterone), progestins (mainly progesterone), estrogens.
- Some hormones are also produced in the brain, which do not take the detour via the hormone factories, but travel directly to the target organ when needed.
- Anterior lobe of the pituitary gland: somatotropin (STH, growth hormone), prolactin (milk-forming hormone), melanocyte stimulating hormone (MSH).
- Posterior lobe of the pituitary gland: oxytocin (labor inducing hormone), vasopressin (ADH, used to regulate fluid balance). Strictly speaking, these hormones are undercover agents: they are already formed in the hypothalamus. But since there officially only the organization, but no production takes place, they reach the pituitary gland by surreptitious means (via nerves) and wait there for a work assignment.
Hormone imbalances – small changes, big consequences
Hormones, control and target organs form a complex system. If something is changed in one place, it can cause adjustments in many other places. The purpose of this finely tuned structure is to optimally adjust the responses of the body and its organs to meet current, mid-term and long-term needs. The control loops and multiple controls ensure that each place does what is beneficial to the whole. But there is also a danger in networking: If one unit does not pull together, this can have major repercussions. Or, to stay with the example from the economy: if a strike breaks out in one of the factories, there is congestion on the traffic routes, foreign suppliers suddenly flood the market with similar products (often cheaper but with poor quality), the bosses change their strategy, memos are buried under the desk instead of being put into action, or the end customers are on vacation or do something different than expected – all this can lead to distortions in the system, in the worst case to collapse. Because of the close interconnections, it is often not at all easy to identify the actual trigger of the problems. And the normal market fluctuations – for example, estrogen levels rise and fall like the stock price in certain cycles, but in a more predictable way – must also be taken into account.
In search of the culprits
Disruptions can occur anywhere in the system and even in several places at once. Thus, the hormone-producing glands or control centers in the brain can be affected just as much as the target organs or the proteins used to transport the hormones in the blood. In addition, there are also tumors that make hormones without worrying about the feedback mechanisms.
Take a step-by-step approach
To cope with this tricky situation, a step-by-step approach is usually useful. Based on the symptoms and findings on physical examination, it is often possible to narrow down which subsystem or hormone may be affected. For example, patients with the disease acromegaly, an increased production of growth hormone, show typical changes in the face and hands, or those with thyroid disorders show typical symptoms such as palpitations or sweating. The concentration of the corresponding hormones in the blood and/or urine is then determined (“hormone level”). It must often be taken into account that this can be subject to (diurnal) fluctuations. Since the concentration of hormones is very low, extremely sensitive laboratory methods are used for this purpose. Many hormones quickly lose their effectiveness outside the body and must therefore be obtained accordingly and transported quickly. At this stage, depending on the suspected cause, the relevant organs can also be assessed using imaging techniques such as ultrasound.
Cause or consequence?
If an elevated or decreased hormone level is indeed found, it must be determined whether it is a cause or consequence.For example, increased thyroid hormones can be produced by a thyroid tumor, but can also be the result of too many releasing hormones being secreted in the brain. This, in turn, may be because that is where the disorder is located or because the wrong message is coming in there that there are too few thyroid hormones in the blood.
Examination Methods
As you can see – it is not so easy to get to the bottom of the matter. Stimulation tests, which check whether and how the body reacts to certain hormones, are helpful. Again, imaging techniques can be used, especially in the context of functional tests. In scintigraphy, for example, a radioactive substance is given that is deposited in a specific organ, for example in the thyroid gland, depending on the metabolic processes. In this way, its function can be assessed and foci of disease can be detected. Hormone tests are always part of the diagnostics in cases of involuntary childlessness. They are also used to monitor therapy: for example, if the hormone level rises again after the removal of a tumor, this indicates a relapse.
Trigger detected – danger averted?
Treatment depends on the cause and ranges from drug therapy (with regular replacement of directly acting hormones or administration of hormones that promote or inhibit secretion) to radio and chemotherapy to surgery (for example, tumor removal). The course and prognosis depend strongly on the cause and cannot be assessed in general terms because of the wide variety of causes.
