What are the side effects of not going outside?

September 22, 2025 •

4 min read

According to the World Health Organization, 60-85% of people globally lead sedentary lifestyles, which often means spending most of their time indoors. Understanding what are the side effects of not going outside is crucial for maintaining both your physical and mental well-being in the modern world.

Quick Summary

Staying indoors for extended periods can lead to a range of issues, including vitamin D deficiency, weakened immunity, poor sleep quality, mental health challenges like anxiety and depression, and physical health problems such as weight gain and bone weakening.

Key Points

Vitamin D deficiency: Lack of sunlight can lead to low vitamin D, causing weak bones, fatigue, and a compromised immune system.
Mental health risks: Reduced exposure to natural light and social isolation significantly increase the risk of depression, anxiety, and seasonal affective disorder.
Sedentary lifestyle problems: An inactive, indoor life leads to weight gain, metabolic issues, heart disease, and bone weakening.
Disrupted sleep patterns: Inadequate natural light can throw off your body's circadian rhythm, resulting in poor sleep quality and daytime fatigue.
Cognitive decline: Spending too much time indoors can lead to mental fatigue, eye strain, and reduced focus.
Social disconnection: Prolonged indoor time often leads to social isolation, which negatively impacts mental and physical health.

The Physical Toll of Indoor Living

Spending too much time indoors comes with a host of physical repercussions, many of which can develop subtly over time. A sedentary lifestyle is a primary driver of these health issues, as being indoors often correlates with lower levels of physical activity.

Vitamin D Deficiency and Weakened Bones

One of the most well-documented consequences of not going outside is a lack of adequate sunlight exposure. Our skin produces vitamin D when exposed to UVB rays, and this vitamin is vital for calcium absorption and bone health. Low vitamin D levels can lead to weakened bones, increasing the risk of fractures and conditions like osteoporosis. Symptoms of this deficiency can include bone and muscle pain, fatigue, and depression.

Weakened Immune System

Vitamin D also plays a crucial role in supporting a strong immune system. A deficiency can lead to a weakened immune response, making you more susceptible to infections like the flu and common cold. Furthermore, prolonged inactivity negatively impacts overall immune function, leaving the body less equipped to fight off pathogens.

Weight Gain and Metabolic Issues

An inactive lifestyle means burning fewer calories. When combined with a disrupted metabolism and poor eating habits that can arise from low mood, this can lead to gradual weight gain and obesity. Sedentary behavior has also been shown to affect the body's ability to process fats and sugars, increasing the risk of metabolic syndrome and type 2 diabetes.

Cardiovascular and Circulatory Health

Lack of movement and outdoor time can negatively impact heart health. Prolonged sitting is linked to poor blood circulation, and the heart muscle weakens without regular activity. This can increase the risk of developing high blood pressure, high cholesterol, heart disease, and stroke. The simple act of a walk outside can do wonders for your cardiovascular system.

The Mental and Emotional Impact

Beyond the physical, staying indoors for long stretches profoundly affects mental and emotional well-being. Natural light, social interaction, and connection to nature all play critical roles in regulating mood and cognitive function.

Disrupted Circadian Rhythms and Poor Sleep

Natural light exposure, especially in the morning, helps regulate our circadian rhythm, the body's internal clock that manages the sleep-wake cycle. Inadequate sun exposure can disrupt this cycle, leading to fatigue during the day and difficulty sleeping at night. Poor sleep quality has a domino effect, impacting mood, concentration, and overall health.

Anxiety and Depression

Sunlight exposure triggers the brain's production of serotonin, a hormone that boosts mood and promotes feelings of calmness. A lack of it can cause serotonin levels to dip, contributing to fatigue and symptoms of depression. Seasonal Affective Disorder (SAD) is a prime example of how reduced sunlight in winter months can trigger depressive episodes. Social isolation, a frequent side effect of staying inside, is also a significant contributor to both anxiety and depression.

Cognitive Function and Attention

Time spent in nature has been shown to improve cognitive abilities and attention spans, offering a much-needed break from the overstimulation of urban environments. Conversely, constant exposure to artificial light and screens indoors can lead to eye strain, mental fatigue, and a reduced capacity for concentration.

Practical Strategies to Combat Indoor Side Effects

Fortunately, mitigating the negative effects of staying indoors is achievable with conscious effort. Here are some strategies to incorporate more of the outdoors into your life, even if your mobility or circumstance is limited.

Bring Nature Inside: Place potted plants in your living space to improve air quality and mood. Research suggests indoor plants can improve focus and stress tolerance.
Optimize Your Indoor Environment: Open curtains wide and allow natural light to flood your space. Position your desk or seating area near a window. Consider using full-spectrum light bulbs, especially during darker seasons, to mimic natural light.
Create an Indoor Movement Routine: Incorporate simple exercises throughout your day. Follow the 20-8-2 rule: 20 minutes sitting, 8 minutes standing, and 2 minutes moving for every 30 minutes of work. This can include walking laps inside, stretching, or using online workout videos.
Stay Socially Connected: Actively counteract feelings of isolation by scheduling video calls with friends and family. A strong social network is crucial for emotional well-being.
Step Out for Small Doses: Even a short 15-minute walk or simply sitting on a balcony or porch can provide valuable sun exposure and fresh air. Research shows that even minimal time outdoors has powerful benefits.

Indoor vs. Outdoor Living: A Comparison

To highlight the importance of outdoor time, consider this comparison of the general effects of living indoors versus outdoors.


Aspect	Prolonged Indoor Living	Regular Outdoor Time
Mental Health	Increased risk of anxiety, depression, SAD.	Reduced stress and anxiety, improved mood.
Sleep Quality	Disrupted circadian rhythm, fatigue, insomnia.	Regulated sleep-wake cycles, better sleep.
Physical Health	Higher risk of obesity, heart disease, weakened bones.	Higher fitness levels, stronger immune system, better heart health.
Vitamin D Levels	High risk of deficiency due to lack of sunlight.	Maintained through natural sun exposure.
Social Connection	Increased risk of social isolation and loneliness.	Opportunities for social interaction and community engagement.
Cognitive Function	Mental fatigue, eye strain, reduced concentration.	Improved focus, memory, and cognitive abilities.

A Balanced Approach to Well-being

It's clear that while modern life often keeps us inside, ignoring the need for outdoor exposure comes at a significant cost. The side effects of not going outside impact our physical bodies, mental clarity, and emotional stability. By understanding these risks, we can be more proactive in our health choices. Making small, consistent changes, like taking regular walking breaks or simply sitting by a window, can significantly improve your well-being. For a deeper look into the health risks of social disconnection, a related issue to prolonged indoor living, you can explore resources from the American Psychological Association. Prioritizing time outdoors is not just a nice-to-have, but a fundamental component of a healthy, balanced life.

Frequently Asked Questions

While individual needs vary, studies suggest that spending at least 20-30 minutes in a natural setting can significantly reduce stress levels. For vitamin D, even 15 minutes of sun exposure, especially around midday, can be beneficial, depending on factors like skin tone and location.

While you can supplement with vitamin D and eat vitamin-rich foods (like fatty fish or fortified products), natural sunlight is the most efficient source for many people. It's often recommended to combine moderate sun exposure with dietary sources to maintain healthy levels.

In areas with limited natural light, especially during winter, it's crucial to be proactive. Consider using a full-spectrum light therapy lamp, which can help regulate circadian rhythms and boost mood. Focus on maximizing exposure to natural light whenever possible, and consult a doctor about vitamin D supplements.

There are many ways to stay active indoors. Try following online exercise videos for yoga, cardio, or strength training. Even simple activities like walking laps around your home or using a standing desk part of the day can help combat a sedentary lifestyle.

To combat social isolation, actively seek connection. Schedule regular video calls with friends and family, join online communities or virtual classes, and make a conscious effort to reach out to others. Volunteering virtually is another great way to stay connected.

Yes, exposure to nature can be very effective in reducing anxiety. Green spaces have a restorative effect, helping to lower stress hormones like cortisol and promoting feelings of calm.

For children, insufficient outdoor time is linked to a higher risk of conditions like ADHD, obesity, and mental health disorders. Outdoor play builds stronger bodies, supports vision, and enhances cognitive function and mood.