How dangerous is a TSH (thyroid stimulating hormone) level of 0.06 uu/ml?

Not good. The exact answer depends on your general health, what other medical problems you current have, your age and the levels of the thyroid hormone ft4 and ft3. The cause of the low TSH is also important. In general, low TSH signifies hyperthyroidism. Hyperthyroidism is more dangerous than hypothyroidism. Death can occur with hyperthyroidism.