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.
World's 10 longest highways. The United States boasts of some of the worldâs longest highways. The Pan-American Highway is the world's longest âmotorable road,â according to Guinness Book of World Records. The Highway links almost all nations in North and South America except for a stretch of 100 km called the Darien Gap, a forest and swampland.