"I constantly hear about patients who are having to change their shirt three to four times a day, who stuff diapers in the sleeves of their shirt under their arms to absorb the moisture, who only buy black clothes and wear multiple layers, who never wear tank tops in the summer because they're afraid of the embarrassment of the sweating," he said.
Pariser said the cause of hyperhidrosis is unknown, but doctors have found some effective treatments, including sending electrical pulses through sweat glands and injecting botulinum toxin type A, or Botox, to paralyze sweat glands.
For a rare disease that cripples the vocal chords' ability to make the most common sound, spasmodic dysphonia has some notable speakers and politicians as sufferers.
"It's a very rare disorder, and there is really very little known about it -- especially back in the '80s and '90s," said Dr. Phillip Song, a laryngologist at the Massachusetts Eye and Ear Infirmary in Boston.
People with spasmodic dysphonia in the media, such as National Public Radio talk show host Diane Rehm, have helped bring spasmodic dysphonia to national attention.
But few people knew what was wrong when Lorraine Rappaport started noticing her voice changing back in the early 1980s while working as a school counselor in California.
"It came on gradually; it isn't like anything that happens overnight," said Rappaport. "My voice got very hoarse, and there were certain letters of the alphabet at the beginning of words that I could not say easily."
Slowly, her condition began to interfere with her job and her communication with others.
"There were times where I had to stop and think, because I wanted to avoid a word because I couldn't say it clearly." Rappaport started to avoid words that began with "h," "ch," "k" or "c" -- a difficult task in English. She had never heard of spasmodic dysphonia at the time, and physicians kept telling her the problem was psychological, especially since she was getting a divorce at the time.
But by the early 1990s, Rappaport found treatment for her condition in a National Institutes of Health clinical trial using Botox injections. The NIH flew her to Maryland from California to receive the low-dose injections, and she started to see an improvement.
Today botulinum toxin type A is used to treat many of the 30,000 Americans who live with this condition.
It's a phobia that filmmakers have loved for years. At a tense moment, someone, usually a man, sees a needle and crumples to the floor.
But it wasn't until 1997 that the mental health community officially recognized needle phobia in the Diagnostic and Statistical Manual of Mental Disorders. Now, mental health experts estimate that needle phobia may affect up to 10 percent of the population, and it may even be inherited.
"Every time I went to the doctor, it was a shop of horrors," says Keith Lamb, an emergency medical technician in Columbus, Ohio, and a long-time needle phobia advocate.
For years, Lamb could not even walk through a dentist's door, because of his needle phobia. But he said his fear of needles truly came to a head when he enrolled in emergency medical management training and was required to "practice" injections with a partner.
"I can dish it out, but I just can't take it," said Lamb.