The draining lava left long, tube-like caverns. Of the four caves in this particular cluster, only Boyd Cave is now open to hikers. Arnold Ice Cave is filled with ice. Skeleton and Wind Cave were open to hikers until 2007, when they were gated closed to prevent vandalism and protect hibernating bats.
On the other hand, asthma is an ongoing chronic condition that has acute flare ups and chronic pulmonary insufficiency due to airway reactions that cause the bronchial tubes to be partially obstructed. This results in shortness of breath, chronic cough, frequent chronic bronchitis, chronic pneumonia and wheezing.
Paroxysmal nocturnal dyspnea is also sometimes called cardiac asthma because its signs and symptoms mimic those of asthma. This term is actually misleading -- the two conditions are very different. While asthma is a chronic condition caused by inflammation of the airways, which can lead to breathing difficulties, paroxysmal nocturnal dyspnea is a sign of heart failure. Paroxysmal nocturnal dyspnea can be accompanied by swelling of the feet or ankles.