Low Immunity in Adults: Causes, Signs, and Solutions

Published: 11/20/2025 | Updated: 11/20/2025

Authored by: Louise Hartnett, B.A.

Edited by: Jemma Strain, B.S. Psychology

If you’re experiencing frequent minor illnesses or recurring symptoms that aren’t easily explained, it could signify chronic stress. Whether it’s persistent colds, infections, or fatigue, stress can impact every body system.¹

There are well-documented links between the stress response and the immune system, with research finding that our immune systems work less effectively during periods of prolonged pressure. This can result in more frequent illnesses and symptoms that are hard to explain.²

Furthermore, symptoms can create additional anxiety around low immunity and getting ill, keeping someone in a state of stress. Fortunately, this cycle can be broken by making certain lifestyle changes and finding the root of the stress.

If stress is affecting your ability to fight off illness, a mental health professional can provide advice and guidance on how to cope. This page can also help, as it explores the frequent illness stress response by discussing:

What low immunity is, its symptoms, and other signs of chronic stress
Causes of low immunity and how stress impacts the immune response
How to recover from low immunity with lifestyle changes and therapy
Where to find professional support

What Is Low Immunity?

Some people are born with a weakened immune system (immune deficiency), an overactive immune system (allergies), or an immune system that turns against their own body (autoimmune diseases).³ These are lifelong genetic conditions that people must constantly manage, but they’re distinct from stress-related immune problems.

Other people can experience low immunity caused by things like stress, poor sleep quality, nutrient deficiencies, smoking, and drinking alcohol. Though these may result in chronic immune issues, they are temporary in the sense that they can be resolved. But what are the signs of low immunity?

Signs of Low Immunity

You may be experiencing low immunity if you’ve noticed frequent illness. For instance, you may have experienced:

Frequent colds or flus
Increased ear or eye infections
Slower healing wounds
Persistent fatigue, even with enough sleep
Recurring cold sores
Frequent stomach upset
Increased headaches, allergy symptoms, or skin rashes

These symptoms are also sometimes known as “burnout physical symptoms,” since they often occur after a period of intense stress. Additionally, sometimes they might arise once a stressful event is over, such as after a period of exams or once you’re back from a long trip.

Alongside illness, you may also be experiencing other physical symptoms of stress and anxiety. For instance:²

Teeth grinding
Hair loss
Muscle tension and soreness
Dizziness
Fast heart rate
Digestive issues, such as nausea
Tingling and numbness
Panic attacks
Hypervigilance and alertness
Loss of appetite or emotional eating

These symptoms can sometimes cause secondary anxiety, leading people to worry that they’ve got a serious underlying health condition. While stress is capable of causing these symptoms, you should still visit your primary healthcare provider if you’re worried about having a serious condition. You can also take a self-test to find out what may be going on for you.

Causes of Low Immunity

Aside from the genetic causes of immunity issues mentioned earlier, psychological stress is strongly linked with immune system dysregulation.

Many factors can cause psychological stress, and stressors are different for everyone. For example, they may be life circumstances or mental health conditions.⁴ Though things like work pressure, the death of a loved one, and breakups are likely to be common stressors for many, their potency will depend on each person. For instance, some people find the Christmas period extremely stressful, while others don’t.⁵

In general, stress can be defined as the response to an event that someone perceives as beyond their ability to cope with.5 Some common causes of psychological stress and reduced immune function include:⁴

Early life adversity: Poverty, maltreatment, neglect, bullying, and sexual abuse have been found to cause inflammation. Therefore, these traumas are strong predictors of immune dysfunction in the short and long term.
Caregiving for others: This is a psychological stressor linked with lowered immune responses and longer wound healing times.
Lower financial and relationship security: These issues could put people at greater risk of chronic stress and accelerated biological aging. For example, research finds that those who make more money and are married for longer are biologically younger than their peers.
Social factors: Issues like troubled relationships, competitive social interactions, and loneliness are linked with inflammation and stress.
Poor sleep: This is another stressor that’s strongly linked to decreased immune function.

Other stressors that may cause immune system issues include depression, anxiety, panic disorders, unemployment, interpersonal conflict, and political instability, among many other factors.

How Does Stress Impact Immunity?

As mentioned, the link between stress and immunity is well-documented, but how does this occur? There are a few stages of this process, and the following is an outline of these:⁵

Initially, our stress response prepares our body for fight or flight. You may notice an elevated heart rate, sudden alertness, or a sense of panic.
Our bodies cannot maintain this level of anxiety for very long. So we move into a second stage where the body is more resistant to stress. We are still producing lower amounts of stress hormones and seem not to be experiencing physical symptoms of panic. However, our body’s resources are less able to cope with other functions (such as tending to immunity threats) as they are still managing the initial stressor.
As we remain in a state of chronic stress for weeks, months, or even years, we may enter a state of exhaustion, fatigue, and illness.

Stress hormones, like cortisol, aren’t always a bad thing. They actually play a crucial role in regulating the immune system, reducing inflammation, and facilitating the healing of injuries. These hormones only become problematic under chronic stress, because we begin to produce too much of them in this state.¹

Immunity can also be compromised by the way stress impacts our gut. When we’re healthy, our intestines have a tight barrier to protect us from food-related bacteria. Stress can weaken this barrier, allowing the bacteria to enter our bodies. Usually, this is handled by our immune system, which causes inflammation to slightly rise, but persistent low-level inflammation can lead to recurring immunity-related symptoms.¹

So, not only does stress make us more susceptible to bacteria entering our bodies, but it also reduces our ability to fight off potential infections.¹

How to Improve Immunity

While stress can be the initial trigger for immunity issues, poor sleep and eating habits can make our symptoms worse. These lifestyle factors can make us feel more rundown, weaken our immune systems further, and increase the likelihood of illness.²

So, changing our behavior is an essential part of coping with chronic stress. Over the following sections, we discuss various ways of doing this.

What You Can Do To Stay Healthy

Strong immunity is cultivated over a longer period of time and is influenced by many different factors. It may be helpful to think of these as small, daily habits that have a larger cumulative effect. Here are some top tips for staying healthy:⁶

Manage your stress levels: Use breathing, meditation, and exercise to contain the physical effects of your anxiety.
Look after your body: Exercising regularly, eating a healthy and balanced diet, and prioritizing sleep can keep your body and immune system working optimally.
Practice good hygiene: Keeping your hands, phone, and food preparation surfaces clean is important for preventing illness. However, there’s only so much you can do in this regard. We are exposed to germs every day, and many people won’t contract illnesses if their immune system is strong.

Challenging the “Boosting” Immunity Myth

You may come across the idea that support for burnout recovery requires you to “boost” your immune system. This idea is flawed because our immune systems don’t work in this instantaneous way. In other words, taking a single supplement or drinking a glass of orange juice won’t “reboot” or “boost” your immunity in any significant way.⁶

To truly reverse the health effects of chronic stress, you must make some lifestyle changes and get to the root of what’s stressful in your life. This is where therapy can be helpful.

Counseling and Therapy for Treating Stress

It may seem intuitive to seek physical remedies for physical sickness, but mental stress often calls for mental and emotional support. Counseling and therapy come in many forms, each able to identify, explore, and heal sources of stress in different ways.

When seeking help for stress overload, you’ll likely come across a few different types of therapy. Here’s what you need to know:

Cognitive-behavioral therapy (CBT) will focus on any thoughts and behaviors that are contributing to your stress levels. Often, CBT helps cultivate personal control, coping strategies, and confidence through exposure to anxiety-inducing situations.
Psychodynamic therapy is less action-based than CBT but is ideal for people who wish to explore past experiences, relationship patterns, or trauma within a safe environment. This approach is often suited to those whose stress stems from unexplored memories and experiences.⁷
Somatic therapy focuses on the mind-body connection, combining talking therapy with techniques from dance, yoga, massage, and meditation. This could be ideal for people holding stress in their bodies and who want to explore the mind-body connection.⁸

Mission Connection: Get Mental Health Support Today

Though physical symptoms of stress can be all-encompassing, it is possible to treat their root cause with therapy, lifestyle changes, or both.

You may wish to speak to someone about how you can better manage your responsibilities or talk through a painful experience from your past that’s still impacting you. Either way, if you’re worried about your immune health and mental wellness, reach out to our team here at Mission Connection.

We take a personalized approach to mental health care, providing treatment that is both flexible to your lifestyle and catered to your specific needs. Browse our facilities, our approach to treatment, or call us today to enquire about our services.