What are the long-term effects of untreated sleep apnea?

Short answer: Untreated obstructive sleep apnea is linked with high blood pressure, heart disease, irregular heartbeat, stroke, type 2 diabetes, depression, memory problems and a higher risk of accidents due to sleepiness. The good news is that sleep apnea responds well to treatment, and regular treatment can reduce many of these risks while improving energy, concentration and mood.

Key takeaways

• Sleep apnea affects the heart, blood vessels, metabolism and brain, not just sleep.
• Repeated oxygen dips and stress surges each night drive many of these effects.
• Sleepiness from untreated apnea raises the risk of road and workplace accidents.
• Early diagnosis and consistent treatment are what make the difference.

Dr. Prashanth's perspective

The long-term effects I worry about are high BP, type 2 diabetes, heart failure and stroke. Equally serious is dozing off behind the wheel, which is a hazard not just to the patient but to the public. Getting evaluated for sleep apnea and treated early can lower the risk of these complications.

— Dr. Prashanth R. Reddy, ENT Surgeon, ENTHealth360

Why does untreated sleep apnea affect the whole body?

Untreated sleep apnea affects the whole body because the same stress cycle repeats many times every night, for years.

In obstructive sleep apnea, the throat collapses during sleep and breathing pauses. Oxygen levels fall. The brain responds with a surge of stress hormones such as adrenaline, which briefly wakes you enough to reopen the airway. Heart rate and blood pressure spike, then settle, then spike again with the next pause.

Over time, these surges keep blood pressure raised even during the day, strain the heart and blood vessels, and promote inflammation. Broken sleep also disturbs hormones that control appetite and blood sugar.

What are the long-term effects?

The long-term effects of untreated sleep apnea fall into a few main groups.

Heart and blood vessels

• High blood pressure, especially the kind that is hard to control with medicines
• Irregular heartbeat, particularly atrial fibrillation
• Heart failure and coronary artery disease
• Stroke

Metabolism

• Type 2 diabetes and insulin resistance
• Difficulty losing weight, partly due to hormone changes from poor sleep

Brain and mood

• Memory and concentration problems
• Depression, anxiety and irritability
• Reduced work performance

Safety

• Excessive daytime sleepiness and a higher risk of road and workplace accidents

These are associations seen across many studies. Not everyone with sleep apnea will develop them, but the risk tends to rise with severity and with years left untreated.

What can you do at home to lower the risk?

You can support your health at home, alongside proper diagnosis and treatment.

• Sleep on your side if your snoring or pauses are worse on your back.
• Avoid alcohol and sedatives in the evening.
• Work towards a healthy weight, as even modest weight loss may reduce apnea severity.
• Stay physically active most days.
• Stop smoking, which inflames the airway.
• Keep regular sleep hours.

If your partner notices you stop breathing during sleep, ask your doctor about an ENT evaluation.

How are breathing, sleep and energy connected here?

Long-term health and daily energy are affected by the same thing: repeated breathing pauses that break sleep.

When deep sleep is broken night after night, the body has less time to recover. Many people adapt so slowly that they forget what feeling rested was like. Once breathing at night is treated, patients have reported sharper focus, more stable mood and more energy for work, exercise and family. These daily changes are often what keeps people motivated to continue treatment.

How does nose breathing support energy and BMR?

Your basal metabolic rate (BMR) is the energy your body burns at rest to keep the heart beating, the brain working and cells repairing. Your cells make that energy using oxygen, so how well you breathe matters.

Nose breathing helps in two ways:

• Warm, moist, filtered air. The nose warms, humidifies and filters each breath before it reaches the lungs. Conditioned air is gentler on the airway lining, which matters in Bangalore's air-conditioned offices and traffic dust. Mouth breathing skips this step and can leave the throat and airways dry.
• Nitric oxide from the sinuses. The paranasal sinuses continuously make nitric oxide (NO), a natural gas. When you breathe in through your nose, small amounts of this NO travel to the lungs, where studies suggest it may help widen tiny blood vessels and improve oxygen uptake. Mouth breathing largely bypasses it.

Nose breathing does not "boost" your BMR. That is set mainly by muscle mass, age, body size and hormones such as thyroid. But comfortable nasal breathing by day, and undisturbed breathing at night, support efficient oxygen supply and deeper sleep, which your body needs to use energy well and recover.

A simple check: sit quietly and breathe through your nose with your mouth closed for two minutes. If that feels difficult, or one side is always blocked, it is worth having your nose examined.

When should you see an ENT?

You should see an ENT for an evaluation if you have signs of sleep apnea, especially with other health conditions.

• Seek urgent medical care for chest pain, sudden breathlessness, fainting, or signs of stroke such as face drooping, arm weakness or slurred speech.
• Seek prompt care if you feel sleepy while driving.
• Breathing pauses or gasping during sleep.
• High blood pressure that is difficult to control.
• Loud snoring with diabetes, heart disease or irregular heartbeat.
• Daytime sleepiness, morning headaches or memory problems.

How an ENT evaluates and treats it

An ENT confirms the diagnosis and looks for blockages in the airway that affect treatment.

Evaluation includes a detailed history, examination of the nose, palate, tonsils and tongue, and a nasal endoscopy. An ENT evaluation shows where the airway narrows, and a sleep test, where needed, measures how many breathing pauses happen per hour and how low oxygen falls. Your ENT may work alongside your physician or cardiologist.

Treatment may include CPAP, which uses gentle air pressure to keep the airway open, an oral appliance, positional therapy, weight management, treatment of nasal blockage, or surgery in selected people. Regular, consistent use matters most. The right option depends on the cause and severity.

Frequently asked questions

Does nose breathing give me more energy? It does not add energy by itself, but it delivers warm, humidified air and sinus nitric oxide to the lungs, which may help oxygen uptake. Together with better sleep, that supports the energy your body uses at rest (BMR) and during activity.

Can sleep apnea damage be reversed? Some effects, such as daytime sleepiness and blood pressure, often improve with treatment. Long-standing heart changes may not fully reverse, which is why early treatment matters.

Is mild sleep apnea dangerous? Mild apnea carries lower risk, but it can still affect sleep quality and energy. Your doctor will advise whether treatment is needed.

Does sleep apnea shorten life? Severe untreated sleep apnea has been linked with higher health risks. Treatment aims to reduce those risks.

References

• Lundberg JO, Farkas-Szallasi T, Weitzberg E, et al. High nitric oxide production in human paranasal sinuses. Nature Medicine. 1995;1(4):370-373.
• Lundberg JO, Settergren G, Gelinder S, et al. Inhalation of nasally derived nitric oxide modulates pulmonary function in humans. Acta Physiologica Scandinavica. 1996;158(4):343-347.
• Keck T, Leiacker R, Heinrich A, Kühnemann S, Rettinger G. Humidity and temperature profile in the nasal cavity. Rhinology. 2000;38(4):167-171.

About the author

Dr. Prashanth R Reddy is an ENT surgeon at ENTHealth360, Bangalore (MS ENT; MBA, IIM Bangalore; Seoul Rhinoplasty Fellowship), seeing patients at Sakra World Hospital, Marathahalli and in Koramangala. His practice focuses on how breathing affects sleep, energy and everyday performance.

Related reading: Why am I always tired even after 8 hours of sleep? · Why do I wake up tired every morning?

For educational purposes only. Not a substitute for medical advice. Please consult a qualified ENT specialist.