welche nebenwirkungen hat l-thyroxin — what does this mean exactly?

The question asks about side effects of L-thyroxine (levothyroxine), a thyroid hormone used for hypothyroidism. The provided context does not contain specific information on side effects – it only discusses TSH tests and general thyroid questions. Therefore, the answer relies on general medical knowledge, not the given sources. Typical side effects occur mainly with overdosing: palpitations, tremor, insomnia, sweating, weight loss, diarrhea, nervousness. With underdosing: fatigue, cold intolerance, constipation, weight gain. Allergic reactions are rare. Important: L-thyroxine is a prescription drug; dosage must be individually adjusted. Self-medication or dose changes without medical supervision are dangerous. Evidence is rated as 'practice' (clinical practice) because side effects are well-documented but not from the provided context. Caveat: No specific studies or PMIDs in the context.