The COVID-19 pandemic may be over, but our immune systems are still feeling the impact. After years of battling constant viral threats, from COVID-19 to seasonal flu and other infections, our body’s defense system is exhausted. Many people continue to experience lingering inflammation, frequent illnesses, and slower recovery times. This extended state of immune stress has compromised us further to chronic illness, including autoimmune diseases and even neurodegenerative diseases such as Parkinson's. So why is our immune system still in trouble? And how do we give it its power back? Understanding immune exhaustion is the beginning of rebuilding our body's natural immunity.

A weakened immune system makes people more susceptible to disease, mental illnesses, and even sleep disorders. Now, new research indicates that immune system depletion may play an important role in the onset of Parkinson's disease, a degenerative neurologic disorder that compromises movement and cognition.

Role of Inflammation in Parkinson's Disease

Dysfunctional immune response is a leading cause of long-standing inflammation within the body, that has been found to contribute towards a multitude of conditions, including cardiovascular conditions, diabetes, depression, and neurodegenerative diseases such as Alzheimer's.

As people age, their immune system naturally becomes less effective. This deterioration, referred to as immune exhaustion, may be a key contributor to the onset and progression of Parkinson’s disease. Rebecca Wallings, a Parkinson’s Foundation Launch Award grant recipient and senior postdoctoral fellow at the University of Florida, believes that an accumulation of exhausted immune cells could be driving neurodegeneration in Parkinson’s patients.

How a Tired Immune System Might Affect Parkinson's?

Parkinson's disease is most commonly linked with the degeneration and loss of dopaminergic neurons—motor nerve cells that produce dopamine, an essential neurotransmitter for movement. While researchers have long suspected inflammation is involved in this neurodegeneration, the mechanisms are not yet well understood.

Wallings' study is on immune cell exhaustion, a process by which aging immune cells fail to control immune responses effectively. Her research indicates that instead of dampening inflammation in Parkinson's patients, attempts should be made to rejuvenate the immune system to regain its functionality.

Energy Deficiency in Immune Cells

One of the major findings of Wallings' work is the function of mitochondrial impairment in immune cell exhaustion. Mitochondria are commonly called the powerhouses of cells, as they are vital for generating energy. As mitochondria age and become inefficient, immune cells fail to function well, potentially accelerating neurodegeneration in Parkinson's disease.

Wallings has found that mutations in the LRRK2 gene, a recognized genetic risk factor for Parkinson's disease, are linked with defective mitochondrial function and immune cell exhaustion. Her current work includes testing various therapeutic approaches to restore mitochondrial function in immune cells with the potential to enhance the immune system and potentially prevent or treat Parkinson's disease.

Will Rejuvenating the Immune System Help in Treatment?

For decades, the standard practice in treating Parkinson's has been to suppress brain inflammation. Yet Wallings' work indicates that instead of slowing down immune responses, restoring the immune system could be a more successful strategy. By addressing mitochondrial impairment and immune resilience, researchers can potentially reverse or slow down Parkinson's disease.

Wallings is now looking into how to rejuvenate immune cells by fixing mitochondria. She studies immune cells from patients with Parkinson's as well as from healthy subjects and performs experiments on animal models to determine if rejuvenation of the immune system could result in improved disease outcomes.

Lifestyle Factors That May Affect Parkinson's Risk

While there is no cure for Parkinson's disease, some lifestyle adjustments may decrease the chances of developing the illness. Since neurodegenerative diseases are associated with chronic inflammation and immune dysfunction, developing habits that enhance immune function might prove helpful.

Diet: There is evidence to suggest that eating in accordance with the Mediterranean or MIND diets, both high in antioxidants, healthy fats, and anti-inflammatory foods, can encourage brain wellness and reduce Parkinson's risk.

Avoiding Dangerous Substances: Restricting alcohol and nicotine use can maintain a robust immune system and suppress inflammation.

Reducing Stress: Chronic stress weakens immune function, so methods such as meditation, exercise, and sufficient sleep can lead to improved overall well-being.

India is facing a growing burden of non-communicable diseases (NCDs), with hypertension and diabetes among the major health concerns.

Experts warned that the risk of both conditions rises after 40, often without noticeable symptoms. Increasing age, weight gain, reduced physical activity, stress, dietary habits, and metabolic changes can all contribute to the risk.

Having hypertension and diabetes together is particularly concerning, as their coexistence can increase the risk of heart disease, stroke, kidney damage, retinopathy, and other complications.

Why Risk Rises After 40?

Dr. Santosh Gupta, Associate Director - CTVS, Paras Health Udaipur, told HealthandMe that several factors contribute to the rising risk after 40.

“After the age of 40, the risk of hypertension and diabetes increases due to factors such as changes in metabolism, reduced physical activity, weight gain, stress and dietary habits. What makes both conditions particularly concerning is that they can develop silently, without noticeable symptoms, while gradually affecting vital organs,” he said.

He added that uncontrolled hypertension can damage the heart, brain, kidneys, and blood vessels, while diabetes can affect the kidneys, eyes, nerves, and cardiovascular system.

"When both conditions occur together, the risk of heart disease, stroke and kidney complications becomes even higher,” Dr. Gupta added.

Because both conditions can remain silent for years, people may have high blood pressure or blood sugar without knowing it.

Also read: Breastfeeding Can Help Reduce Mothers' Risk of Type 2 Diabetes, Breast Cancer and More

Hypertension And Diabetes Often Coexist

A recent hospital-based analysis found that hypertension and diabetes frequently occur together, with their coexistence rising sharply from around age 40 among Indians.

The study, conducted by the Department of Clinical Research and Preventive Health Program at Max Healthcare, analyzed health records of more than 56,000 adults who underwent preventive health check-ups between January 2021 and December 2024.

Nearly 5% of adults had both conditions. Their coexistence increased rapidly from around 40, continued rising until approximately 58 and gradually reached nearly 17% by around age 70.

People with diabetes were nearly four times more likely to have hypertension, while those with hypertension were about 2.5 times more likely to have diabetes.

Dr. Abhaya Indrayan, Biostatistics Consultant, Max Healthcare, said the findings support screening for both conditions rather than assessing them separately.

Why Screening After 40 Matters

Read More: Confused By Your Cholesterol Report? Here's What LDL And ApoB Really Mean

Experts said that preventive healthcare should go beyond checking for individual diseases. Adults over 40 should routinely assess key cardiometabolic risk factors, including blood pressure and blood sugar.

Screening can help detect hypertension, diabetes or prediabetes early, when lifestyle changes and treatment can help prevent or delay complications.

“This is why regular screening after 40 is important, even for individuals who feel completely healthy. A routine blood pressure check, fasting blood glucose or HbA1c test can help identify hypertension, diabetes or prediabetes at an early stage, when timely lifestyle changes and medical intervention can prevent or delay complications,” Dr. Gupta said.

“Screening should not be viewed only as a diagnostic exercise; it is an opportunity to understand one’s health risks and take corrective measures before the disease begins to cause irreversible organ damage,” he added.

How To Lower The Risk

Preventive care also involves addressing modifiable risk factors. Regular physical activity, maintaining a healthy weight, limiting salt, sugar and highly processed foods, getting adequate sleep and avoiding tobacco can help lower the long-term risk.

For those already diagnosed with hypertension or diabetes, regular monitoring and adherence to prescribed treatment are important to reduce the risk of complications.

With the risk of both conditions rising after 40, experts recommend making routine health checks part of regular healthcare—even when there are no obvious symptoms.

Amid the ongoing monsoon season, Delhi-NCR is seeing a rise in H1N1 influenza cases, with Delhi reporting 1,344 cases so far this season.

The figure is nearly six times higher than the 229 H1N1 cases recorded during the same period last year, The Times of India reported.

According to health officials, Delhi recorded around 4,000 influenza cases last year, most of them caused by H3N2. This year, H1N1 is the dominant strain. Both H1N1 and H3N2 are subtypes of Influenza A and spread mainly through respiratory droplets.

What Is H1N1 and Why Is Testing Important?

H1N1 is a subtype of Influenza A and can cause sudden fever, cough, sore throat, headache, body aches and fatigue. These symptoms can overlap with those of other seasonal influenza strains, COVID-19 and respiratory syncytial virus (RSV), making it difficult to identify the infection based on symptoms alone.

Dr Aijaz Ilmi, Senior Consultant – Metabolic Diseases, Pacific OneHealth Hospital, told HealthandMe that testing is particularly important when fever or respiratory symptoms persist or worsen, especially among older adults, young children, pregnant women and people with diabetes, obesity, heart or lung disease, or compromised immunity.

“With the current rise in H1N1 cases in Delhi, we are also seeing other seasonal respiratory infections, including Influenza A and B, COVID-19, RSV and other respiratory viruses. At the same time, the monsoon season brings an increased risk of mosquito-borne illnesses such as dengue.

“The key message is, don’t panic, but don’t dismiss a persistent fever as ‘just a viral’. Early recognition is particularly important in vulnerable individuals.”

H1N1 vs Other Respiratory Infections: How Are They Different?

H1N1 can be difficult to distinguish from other respiratory infections because many of them cause similar symptoms.

• H1N1 and other seasonal influenza strains: Both can cause sudden fever, cough, sore throat, headache, body aches and fatigue. Symptoms alone generally cannot determine whether the infection is H1N1 or another influenza strain.

• COVID-19: COVID-19 can cause fever, cough, sore throat, congestion and fatigue. Some people may also experience changes in or loss of taste or smell, while gastrointestinal symptoms can occur.
• RSV: RSV commonly causes a runny nose, cough and wheezing. It can be more severe in infants, older adults and people with certain underlying conditions. In young children, it can cause bronchiolitis and breathing difficulties.
• Dengue: During the monsoon, dengue can also cause fever, headache, body aches and fatigue, which may initially resemble a viral respiratory infection. However, dengue is spread by mosquitoes rather than respiratory droplets and does not typically cause cough or sore throat.

How Can H1N1 and Other Infections Be Prevented?

Dr Sharwari Sudhir Dabhade, Consultant - Internal Medicine, Diabetology & Endocrinology, Madhukar Rainbow Children's Hospital, told HealthandMe that prevention should focus on reducing exposure and maintaining good hygiene. Other measures to reduce transmission include:

• Washing hands frequently.
• Covering mouth and nose while coughing or sneezing.
• Maintaining good indoor ventilation.
• Avoiding crowded or poorly ventilated places when respiratory infections are circulating.
• If you have respiratory symptoms, limit close contact with others and wear a mask.
• Getting vaccinated against influenza, particularly if you are an older adult, young child or have an underlying health condition.
• Prevent mosquito breeding and take precautions to avoid mosquito bites to reduce risk of dengue.

When Should You Seek Medical Help?

Most viral respiratory infections recover with supportive care. However, should seek prompt immediate medical assessment in cases of

• breathlessness
• persistent high fever,
• chest pain,
• confusion,
• dehydration,
• falling oxygen saturation
• significant worsening of weakness.

People with inflammatory bowel disease (IBD) may face a higher risk of depression, anxiety and other psychiatric disorders years before they are diagnosed with the gut condition, a new study has discovered.

The study, published in Clinical Gastroenterology and Hepatology, found that the risk of psychiatric disorders began rising two to three years before an IBD diagnosis, peaked shortly after diagnosis and remained elevated for as long as a decade.

Researchers from Karolinska Institutet and other Swedish institutions analysed data from 43,862 people with IBD, comparing them with nearly 179,000 individuals from the general population and more than 26,000 IBD-free full siblings.

The sibling comparison was key as it helped researchers examine whether shared genetic or early-life environmental factors could explain any association.

Risk Of Mental Health Issues Increase Before IBD Diagnosis

Also read: Monsoon Gut Health: Addressing The Rise In Rotavirus And Viral Gastroenteritis Cases

The study found that the risk of developing any mental health disorder was already 15% higher two years before IBD diagnosis. It increased further around the time of diagnosis, reaching a roughly 50% higher risk within the first six months.

Although the risk reduced afterwards, it remained about 19% higher even 10 years after diagnosis. Major depressive disorder, anxiety disorders and substance misuse accounted for much of the increase.

Antidepressant and anti-anxiety medication use also began rising around a year before the IBD diagnosis.

Researchers called for mental health screening to begin early, including during the initial gastroenterology evaluation.

“It is time to actively manage psychiatric conditions in patients with IBD,” said Jiangwei Sun, PhD, the study’s lead author.

Why Depression And Anxiety Appear Before IBD Is Diagnosed?

Also read: Following A Western Diet? Changes In Your Gut Bacteria Could Increase Colon Cancer Risk

IBD includes Crohn’s disease and ulcerative colitis, autoimmune conditions that cause inflammation in the digestive tract.

One possible explanation is the gut-brain axis, the two-way communication system connecting the digestive system and brain.

Inflammation, changes in gut bacteria and abnormal immune activity may affect brain function and overall mood. At the same time, stress and psychological distress can affect the gastrointestinal symptoms.

But researchers caution that the study merely shows an association, not proof that IBD directly causes depression or anxiety.

Some people may experience subtle or unexplained gastrointestinal symptoms before receiving an official diagnosis, while the uncertainty and disruption caused by chronic symptoms could also affect mental health.

Mounting Evidence

The findings follow previous research that shows psychiatric symptoms can surface before the patient is diagnosed with IBD.

A 2023 study examining longitudinal health records found that anxiety and depression occurred more frequently among people who were later diagnosed with IBD.

In a 2024 systematic review and meta-analysis, it was observed that patients with a history of depression may have a small-to-moderate increased risk of subsequently developing IBD, suggesting that the relationship between the gut and mental health could work in both directions.

The new findings therefore signal that mental health symptoms may sometimes arrive years before IBD itself is formally diagnosed in patients.

For doctors, researchers say this highlights the need to treat IBD as more than a digestive disease, with psychological support and screening considered part of long-term care.