The hot, humid and long days of summer move many family gatherings and social events to the more pleasant evening hours. The heat index and late bed times, however, can cause problems for older people.

The weather can trigger shortness of breath, and many seniors are tired by 7 p.m. The good news? Both these symptoms are treatable and should not be written off as signs of aging, doctors say.

Wanting to go to bed early is called "advanced sleep phase syndrome," which occurs when a person's internal clock, or circadian rhythm, is disturbed. It causes people to go to bed anywhere from 6 to 9 p.m., and wake up early, sometimes hours before dawn.

"They wake up at 5 a.m. feeling like they have insomnia," said Dr. Raman Malhotra, co-director of the St. Louis University SLUCare Sleep Disorders Center. "Their internal clocks are not set to what society's is."

Malhotra said only about 1 percent of adults have the syndrome, but the prevalence grows as people age, leading many to think it is normal for older people to go to bed that early.

"People think they're retired and don't have a lot of activities planned. But older adults complain they cannot stay awake for any activities with grandkids or kids or friends," he said.

Treatment is easy, because exposure to light can change sleep patterns, Malhotra explained. When seniors start to feel sleepy, they should open the blinds and spend time outside. When they wake up at 5 a.m., they should keep the curtains drawn and not let light in. Light treatment is especially opportune this time of year when days are long, he said. Repeated treatment should re-adjust their internal clock.

Treating the syndrome with sleeping pills won't do the trick, Malhotra added, because they would have to be taken when waking up and could cause drowsiness during the day.

Respiratory problems are also misunderstood among the elderly, according to Dr. Raymond Slavin, professor of internal medicine at SLU and SLUCare allergist. Asthma — which can be triggered by heat and humidity — is often misdiagnosed as allergies or mistaken for other conditions such as bronchitis.

"Oftentimes, it's undiagnosed because both the patient and physician feel that getting short of breath is just part of the aging process," he said. "You can't do the things at 74 that you did at 45."

Plus, asthma is perceived as a young person's disease, Slavin said. Many people don't know that 40 percent of first-time asthma cases occur in those age 40 or older.

Asthma's major symptoms are cough and shortness of breath, often in the middle of the night. It's exacerbated by physical exertion; or exposure to pollen, mold or pet dander, Slavin said.

"The importance of making the diagnosis is that asthma is treatable with appropriate medications," he said.

Asthma that goes undiagnosed is dangerous. Slavin said 60 percent of asthma deaths occur in patients older than 65, and older adults are the only age group in which the disease is getting worse.

Even in the dog days of summer, grandma and grandpa can breathe easier. They can even sleep in on weekends. "Patients can lead a very normal life," Slavin said.