Hypopnea means breathing that’s shallower or slower than what’s necessary to meet your body’s requirements, or underbreathing. Hypoventilation describes the situation wherein a reduced amount of air enters the alveoli in your lungs, resulting in hypoxia and hypercapnia. Hypoxia is the state of low oxygen in your blood, while hypercapnia means your blood contains too much carbon dioxide.
Hypocapnia’s low blood oxygen level, aka hypoxia, causes symptoms of:
- cyanosis
- sleepiness
- shortness of breath
- fatigue without much effort
Severe hypoxia can cause cerebral vasoconstriction, which may lead to quick episodes of dizziness, visual disturbances and anxiety.
Holding your breath is a voluntary hypopnea condition of hypoventilation causing hypoxia. And some highly trained athletes may breath less than the untrained, yet they’re fewer breathes still meet their body’s needs.
Some health conditions that can cause involuntary hypopnea, hypoventilation and/or hypoxia are:
- alcohol abuse
- high altitude sickness
- COPD, emphysema, bronchitis
- primary alveolar hypoventilation
- congenital central hypoventilation syndrome
- physical ~ scoliosis, nasal septum deformation
- reduced lung function caused by smoking, air pollution
- weakened respiratory muscles ~ motor neurone disease
- obesity hypoventilation syndrome ~ obesity, overweight
- sleep hypopnea ~ mimics obstructive sleep apnea syndrome with no apneas
- drugs side effect, overdose ~ sedatives, opiates, benzodiazepines, barbiturates
- neuromuscular disease ~ myasthenia gravis, ALS, Guillain-Barré syndrome, muscular dystrophy
- neurologic disorders - encephalitis, brainstem disease, trauma, poliomyelitis, multiple sclerosis
The consequences of hypopnea and hypoventilation can be an associated cause for other health conditions, such as:
- stroke
- impotence
- hypertension
- memory loss
- psychiatric problems
- cognitive dysfunction
- coronary heart disease
And extreme case of hypercapnia can cause acidosis, myoclonus, seizures and respiratory failure.