If your fat an have a double chin how would you know of you had ludwigs angina? would the sweeling be very noticeable?

Yes: Swelling would be severe, especially under the tongue at the floor of mouth. Swelling ; pain arise from infection, often dental in origin. Swelling under the tongue can lead to difficulty breathing. Er visit is recommended if you are concerned about this.

Yes, extremely: The area under your chin would be extremely firm and very tender. There would be no mistaking ludwigs angina from a normal neck, even a neck with a large double chin.

Severely ill: Ludwig's angina is a severe, rapidly spreading infection with fever, chills, and choking (one of the contributors to the etymology of the word "angina").If you lift the tongue up, you may see swelling of the floor of the mouth.Given the risk of the airway closing off from the swelling, urgent medical care is required, and emergency care if making noises when breathing (911 call in the US)