)
Actor Keerthy Suresh recently opened up on Instagram saying that she stayed awake for 41 consecutive hours while managing back-to-back film shoots across multiple industries. Sharing details of her hectic schedule, she said the marathon work stint involved nearly 20-hour workdays, with barely an hour to recover before moving on to the next assignment. Her candid revelation has sparked conversations about the health risks of prolonged sleep deprivation. While an occasional late night may leave you feeling groggy, staying awake for nearly two days can have far more serious consequences, affecting everything from brain function and heart health to immunity and mental wellbeing. Experts warn that prolonged sleep deprivation pushes the body into a state of physiological stress, increasing the risk of accidents, impaired judgment, and long-term health complications.
What Happens To The Body After 41 Hours Without Sleep?
According to Dr Harish Verma, Director, Pulmonology, ShardaCare-HealthCity, remaining awake continuously for 41 hours affects multiple organs simultaneously. "Staying awake continuously for 41 hours places the body under significant physiological stress, and the effects extend far beyond simply feeling tired," Dt Verma adds.
Sleep is not simply a period of rest it is when the body repairs tissues, regulates hormones, strengthens immunity, consolidates memory, and restores energy reserves. Missing this restorative period disrupts several essential biological processes.
The Brain Goes Into Survival Mode
One of the first organs to suffer is the brain. According to Dr Amit Agarwal, Senior Consultant, Neurology, Amrita Hospital, Faridabad, the brain begins prioritising basic survival over higher-level thinking. "The brain goes into survival mode after 41 hours without sleep, so it's not just 'being weary'. The prefrontal cortex, which is in charge of judgment, decision-making, and impulse control, is among the first areas of the brain to be sacrificed," Dr Agarwal adds. The prefrontal cortex plays a crucial role in:
- Decision-making
- Problem-solving
- Planning
- Concentration
- Emotional regulation
- Impulse control
As sleep deprivation continues, these abilities become progressively impaired.
Poor Judgment Despite Feeling Fine
One of the most dangerous aspects of prolonged sleep deprivation is that people often fail to recognise how impaired they have become. Dr Agarwal explains, "Because of this, even when their performance is declining, sleep-deprived persons frequently feel confident. The brain becomes incapable of appropriately evaluating its own errors. We refer to this as a risky mismatch between skill and confidence." This false sense of confidence can increase the risk of:
- Road accidents
- Workplace injuries
- Poor decision-making
- Medical and industrial errors
Memory And Concentration Also Suffer
Sleep plays a vital role in processing information and storing memories. Dr Agarwal says, "Sleep is when the brain does some of its most complex upkeep and repair work; it is not a stop in brain activity." Without adequate sleep, people may experience:
- Difficulty concentrating
- Slower thinking
- Poor memory
- Reduced learning ability
- Mood swings
- Irritability
Repeated episodes of sleep deprivation may also affect long-term cognitive health.
Effects On The Heart
Sleep deprivation doesn't just affect the brain it also places considerable strain on the cardiovascular system. According to Dr Verma, lack of sleep also triggers an increase in stress hormones such as cortisol and adrenaline, which can raise heart rate, blood pressure, and systemic inflammation. Over time, repeatedly elevated stress hormones may increase the risk of:
- High blood pressure
- Irregular heart rhythms
- Heart disease
- Stroke
Even healthy individuals may notice palpitations or elevated blood pressure after prolonged sleep loss. "The brain is equally affected. After 24–36 hours without sleep, attention, reaction time, decision-making, memory, and emotional regulation begin to deteriorate significantly. Beyond this, individuals may experience microsleeps, poor judgment, mood changes, and even temporary hallucinations. These cognitive changes can make activities such as driving or operating machinery extremely dangerous," says Dr. Amit Kumar, Associate Director and Head - Interventional Cardiology, Sarvodaya Hospital, Sector-8, Faridabad.
Impact On Breathing And Lung Health
From a sleep medicine perspective, prolonged wakefulness also affects respiratory health. Dr Verma notes that sleep deprivation can:
- Disrupt normal breathing patterns during recovery sleep
- Reduce respiratory muscle performance
- Interfere with efficient oxygen utilisation
People with conditions such as:
- Obstructive sleep apnoea
- Asthma
- Chronic lung disease
- Cardiovascular disease
may experience even greater health consequences because sleep loss can worsen airway inflammation and reduce cardiopulmonary resilience.
Microsleeps Can Become Dangerous
One of the most concerning effects after nearly two days without sleep is the development of microsleeps. These are brief, involuntary episodes of sleep lasting just a few seconds. Although they may seem harmless, microsleeps occurring while driving, operating machinery, or performing safety-sensitive tasks can lead to serious accidents because the person is temporarily unaware of their surroundings.
Can The Body Recover?
For otherwise healthy individuals, adequate rest can reverse many short-term effects of sleep deprivation. However, experts caution that repeatedly staying awake for prolonged periods can have lasting health consequences. According to Dr Verma, chronic severe sleep deprivation has been associated with increased risks of:
- Hypertension
- Cardiac rhythm disorders
- Reduced immunity
- Metabolic disorders
- Anxiety
- Depression
- Reduced cognitive performance
Recovery involves not just sleeping longer once, but restoring healthy sleep habits consistently over time.
How Much Sleep Do Adults Need?
Most adults should aim for 7-9 hours of quality sleep every night, according to sleep experts. Good sleep hygiene includes:
- Maintaining a regular sleep schedule
- Limiting caffeine late in the day
- Reducing screen time before bed
- Creating a quiet, dark sleeping environment
- Managing stress through relaxation techniques
Consistent, high-quality sleep supports healthy brain function, cardiovascular health, immunity, emotional wellbeing, and overall productivity. Keerthy Suresh's 41-hour no-sleep stretch highlights the intense demands many professionals face, but experts warn that prolonged sleep deprivation should never become routine. Staying awake for nearly two days affects judgment, memory, concentration, heart function, breathing, and overall health. While the body can recover after adequate rest, repeatedly sacrificing sleep may increase the risk of serious long-term health problems. Prioritising seven to nine hours of quality sleep each night remains one of the simplest and most effective ways to protect your brain, heart, lungs, and overall wellbeing.
Disclaimer: This content including advice provides generic information only. It is in no way a substitute for a qualified medical opinion. Always consult a specialist or your own doctor for more information. NDTV does not claim responsibility for this information.