Dilaudid (hydromorphone) is a strong opioid pain medication, and like all opioids, it can cause several side effects. Common reactions include dizziness, drowsiness, nausea, constipation, and headache. More serious risks involve slowed breathing, low blood pressure, and potential dependency with prolonged use. For individuals with Low Thyroid, these side effects may be more pronounced because hypothyroidism can already cause fatigue, slow metabolism, and sensitivity to medications. Combining Dilaudid with a low thyroid condition may increase drowsiness or reduce alertness, so careful monitoring by a healthcare professional is essential. Always discuss any concerns with your doctor before use.