Overview. If you frequently experience shortness of breath or you hear a whistling or wheezy sound in your chest when you breathe, you may have asthma â a chronic condition that causes inflammation and narrowing of the bronchial tubes, the passageways that allow air to enter and leave the lungs.
1 At 47,958 kilometres (29,800 miles) in total length, the Pan-American Highway is the longest road in the world.  The road starts in Alaska, North America and ends in the lower reaches of South America.
U.S. Route 1 (US 1) is a major northâsouth U.S. Highway that serves the East Coast of the United States. It runs 2,369 miles (3,813 km), from Fort Kent, Maine, at the CanadaâUS border, south to Key West, Florida, making it the longest north-south road in the United States.