I am having 0.6mm umbelical hernia is this dangerous to me?

Umbilical Hernia: An umbilical hernia that small should not be a problem.

Unlikely: These small hernias may be present for years without causing any problem. If it gets larger, or causes pain, see a general surgeon for a consultation.

Not usually: Umbilical hernias are very common. Most are asymptomatic or cause abdominal pain. A small number can develop bowel incarceration or strangulation and require emergency surgery. If this happens you will get escalating pain and a lump that doesn't reduce. If you are asymptomatic it is usually safe to watch and wait. If you develop symptoms if incarceration or strangulation see MD urgently

Not at 0.6 mm: even at 6 mm, it should not cause trouble. It could enlarge over time, and then become more symptomatic and problematic