Remember there is only one way you can get asthma. Asthma during sleep is also as simple. When the human body becomes horizontal, the resistance to deeper breathing is reduced. Ie it is a lot easier to breathe more deeply when you are lying down. As soon as you become unconscious, your breathing gets deeper and deeper, simply because of the horizontal position.
Some people, particularly children, will develop asthma within 2 hours of going to bed. The night cough often starts at this time, because the CO2 is low and mucus production has increased.
The other common time for problems is between 3:30 and 5:00 am, when the body is at it’s deepest point of sleep, which also causes the breathing to be greater at this time. You may notice that people start to snore, or they wake with full bladders, or, if children, they may ‘wet the bed’ at this time. These are all associated with low CO2 that is caused by overbreathing.
Snoring is simply your body attempting to reduce the airflow by swelling the throat and reducing the size of the pipe. Obstructive sleep apnea is a more severe defence of this type.
In terms of bladder problems, these are usually caused in sleep by spasms of smooth muscle in response to low CO2. The same smooth muscle which lines the airpipes and bloodpipes, also lines the bladder.
When CO2 is low, it will constrict making the bladder feel full. This will wake an adult, but a child may simply urinate.
Sleeping is a danger time. The majority of heart attacks and strokes occur at the time of deepest sleep and therefore the deepest breathing.
Asthmatics will very commonly wake feeling constricted or coughing after deepest sleep.
What Can We Do About It?
The first point is that the better our breathostat is set during the day, the less problem we will have with sleep. So simply by doing our shallow breathing during the day, the better our nights will be.
More practical steps include not sleeping on your back. It is far easier to breathe more deeply on your back, as there is less resistance. Lie down and test it. If you rest on your side, it is physically more difficult to take a deep breath. This is easily seen in people who snore. They often only do so while on their back. Rolling them on their side usually stops or reduces the noise.
So step one is to sleep on your side not your back. This will not make your breathing good, only less bad. We already know the effect of food on breathing as it increases it. If you lie down after eating a large meal, you will have a double whammy.
Your breathing will be increased by the food and by your horizontal position.
Do not have meals or high protein snacks [like warm milk or hot chocolate] or alcohol before going to bed.
Your Mouth, Possibly the greatest factor in nocturnal asthma is the fact that while asleep you have no conscious control over whether or not you breathe through your mouth or nose. Your mouth can just drop open.