Around 2/3 of women experience shortness of breath as a part of a normal pregnancy. Neurological conditions such as spinal cord injury, phrenic nerve injuries, Guillain-Barre syndrome, amyotrophic lateral sclerosis, multiple sclerosis and muscular dystrophy can all cause an individual to experience shortness of breath.
On August 2, 1964, the U.S. destroyer Maddox exchanged shots with North Vietnamese torpedo boats in the Gulf of Tonkin. Two days later, the Maddox and another destroyer reported once again coming under fire.
The Gulf of Tonkin incident proved to be the next apparent incident. True, the Johnson administration jumped at the chance to use the apparent attack to ask for the Gulf of Tonkin Resolution, and later on tried to cover up the fact there was no second incident, but I do not belive that the Johnson faked the attack.