• Published on: Jul 07, 2020
  • 2 minute read
  • By: Dr Rajan Choudhary

Asymptomatic COVID Infections – Are You Safe?

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Asymptomatic COVID infections – are you safe?

Patients with COVID usually exhibit signs of coughing, fever, and fatigue. This can develop into further respiratory problems including difficulty breathing, pneumonia in both lungs, and in severe cases the need to ventilate a patient in an intensive care setting. But what if you are asymptomatic? Do you need to worry? Surely you get the benefits of immunity without the dangers of life-threatening symptoms.

In our previous blog, we discussed how a study showed 41% of people with COVID were asymptomatic. However, they had the same viral load as their symptomatic counterparts. This paper published in Nature Medicine suggests that even the asymptomatic patients developed signs of lung inflammation without showing any outward symptoms. Could asymptomatic patients still be damaged by COVID? It's not easy to study this subset of patients, as they do not get tested routinely or present to hospital for examination or investigation.

This study looked at 37 individuals in the Wanzhou District who were diagnosed with COVID via swab test but did not show any symptoms before the test or during hospitalization. These patients were found through the extensive contact tracing program set up in Central China. Whilst in hospital 57% showed abnormalities in the lung fields on a CT scan, including the “ground glass” appearance classic for COVID pneumonia. These changes could be due to fluid or blood in the area or due to inflammation caused directly by the infection.

What does this mean for the individual in the long term? This is difficult to say, especially since COVID has only been around for a few months so long term follow up is simply impossible to state accurately. Depending on the size and severity of the inflammation it may resolve spontaneously with no lasting damage, or the inflammation could cause scarring of the lung tissue that only becomes evident several years or decades down the line. It's difficult to tell.

The study also looked at two other factors in these patients. Compared to their symptomatic counterparts, asymptomatic patients were found to shed viral particles for several more days. It is unclear the significance of this, or whether this makes them more infective or prone to transmitting the infection for a longer period of time. It does add support to the theory asymptomatic people should not believe themselves exempt from spreading the infection.

Secondly, the study looked at the prevalence of antibodies present in the patient's blood. These antibodies can be used as a surrogate for immunity. In theory, after infection occurs our body has the ability to rapidly produce these antibodies against the virus in the event of a second infection. This would neutralize the infection before it could develop into a serious disease.

Looking at these antibodies the researchers found antibody levels against the SARS and MERS virus to last over 2 years. However, against SARS-CoV-2, the antibody levels fall within 2-3 months, providing only a short duration of immunity. This is worrisome for individuals and countries hoping to achieve herd immunity or at least immunity to the virus after a mild or asymptomatic infection.

So what should we take away from this? Perhaps an asymptomatic infection is not the perfect scenario. Damage does occur to your lungs, albeit temporary damage. You are still able to spread it to vulnerable people. And your immunity may not last as long as other infections.

Therefore be safe. Maintain social distancing, follow government advice on wearing a mask. And if you can, avoid excessive socializing or close contact with lots of other people. The virus hasn’t gone away, and it is still dangerous. 

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caffeine

Health Problems Linked to Excessive Caffeine Intake: When Too Much Becomes Harmful

Caffeine is one of the most widely consumed stimulants in the world. Found in coffee, tea, energy drinks and many soft drinks, it is often used to improve alertness and combat fatigue. While moderate caffeine consumption can be safe for most people, understanding the health problems linked to excessive caffeine intake is important, especially as daily consumption levels continue to rise in India.

Urban lifestyles, long working hours and increased reliance on energy drinks have made caffeine overconsumption a growing public health concern.

 

How Caffeine Works in the Body

Caffeine stimulates the central nervous system by blocking adenosine, a chemical responsible for promoting sleep and relaxation.

This results in:

  • increased alertness

  • faster heart rate

  • heightened mental activity

However, overstimulation places stress on multiple body systems.

 

What Is Considered Excessive Caffeine Intake?

According to WHO and global health guidelines:

  • up to 400 mg per day is considered safe for most healthy adults

Excessive intake occurs when:

  • multiple caffeinated beverages are consumed daily

  • energy drinks are used frequently

  • caffeine is consumed late in the day

Many people unknowingly exceed safe limits.

 

Nervous System Overstimulation

Excess caffeine overstimulates the brain.

Common symptoms include:

  • restlessness

  • nervousness

  • tremors

  • irritability

Chronic overstimulation can worsen stress and reduce emotional stability.

 

Anxiety and Panic Symptoms

Caffeine increases adrenaline release.

This can:

  • trigger anxiety attacks

  • worsen panic disorder

  • increase feelings of unease

ICMR mental health studies note caffeine as a common trigger for anxiety symptoms in sensitive individuals.

 

Sleep Disruption and Insomnia

Sleep is one of the first systems affected.

Excessive caffeine:

  • delays sleep onset

  • reduces deep sleep

  • shortens total sleep duration

Even caffeine consumed 6–8 hours before bedtime can impair sleep quality.

 

Impact on Heart Health

High caffeine intake affects the cardiovascular system.

Possible effects include:

  • increased heart rate

  • palpitations

  • irregular heart rhythm

People with underlying heart conditions are particularly vulnerable.

 

Blood Pressure Elevation

Caffeine temporarily raises blood pressure.

Chronic excessive intake may:

  • worsen hypertension

  • increase cardiovascular risk

NFHS-5 data highlights rising hypertension prevalence in India, making caffeine moderation important.

 

Digestive System Problems

Caffeine stimulates stomach acid production.

This can cause:

  • acidity

  • heartburn

  • gastritis

  • bloating

People with sensitive digestion may experience symptoms even at lower doses.

 

Dependency and Withdrawal Symptoms

Regular high intake leads to caffeine dependence.

Withdrawal symptoms include:

  • headaches

  • fatigue

  • irritability

  • difficulty concentrating

Dependence reinforces overconsumption cycles.

 

Effect on Bone Health

Excessive caffeine:

  • increases calcium loss through urine

  • may affect bone density over time

This is particularly concerning for older adults and women.

 

Dehydration and Electrolyte Imbalance

Caffeine has a mild diuretic effect.

High intake without adequate hydration may lead to:

  • dehydration

  • muscle cramps

  • fatigue

Hot climates increase this risk.

 

Impact on Blood Sugar and Metabolism

Caffeine affects glucose metabolism.

Excessive intake:

  • worsens insulin sensitivity

  • increases stress hormone release

This may increase diabetes risk when combined with poor lifestyle habits.

 

Energy Drinks and Hidden Risks

Energy drinks often contain:

  • very high caffeine levels

  • added sugar

  • stimulants

Lancet reports associate energy drink overuse with heart rhythm disturbances and metabolic stress.

 

High-Risk Groups

Certain individuals should be especially cautious:

  • people with anxiety disorders

  • those with heart disease

  • pregnant women

  • individuals with sleep disorders

Safe limits may be lower for these groups.

 

Signs You May Be Consuming Too Much Caffeine

Warning signs include:

  • frequent palpitations

  • chronic insomnia

  • persistent anxiety

  • digestive discomfort

  • reliance on caffeine to function

These signals indicate the need for reduction.

 

How to Reduce Caffeine Intake Safely

Effective strategies include:

  • gradual reduction rather than abrupt stopping

  • switching to decaffeinated options

  • avoiding caffeine after mid-afternoon

  • improving sleep and nutrition

Small steps prevent withdrawal symptoms.

 

Healthier Alternatives for Energy

Better ways to improve energy include:

  • adequate sleep

  • balanced meals

  • hydration

  • regular physical activity

These support sustained energy without overstimulation.

 

Role of Preventive Health Awareness

Preventive healthcare focuses on:

  • identifying lifestyle triggers

  • reducing dependency habits

NITI Aayog highlights lifestyle modification as key to non-communicable disease prevention.

 

Long-Term Health Consequences of Ignoring Excess Intake

Chronic caffeine overuse increases risk of:

  • sleep disorders

  • anxiety and mood issues

  • heart rhythm problems

  • digestive disorders

These conditions often develop gradually.

Conclusion

The health problems linked to excessive caffeine intake extend beyond temporary jitters or sleep loss. Chronic overconsumption strains the nervous system, disrupts sleep, affects heart rhythm, worsens anxiety and impacts digestion and metabolism. While caffeine can be enjoyed safely in moderation, recognising personal limits and maintaining balance is essential for long-term health. Listening to early warning signs and adopting healthier energy habits can prevent serious health consequences.

 

References

  • World Health Organization (WHO) – Caffeine Intake and Health Guidelines

  • Indian Council of Medical Research (ICMR) – Nutrition and Mental Health Studies

  • National Family Health Survey (NFHS-5) – Hypertension and Lifestyle Risk Data

  • Lancet – Energy Drinks, Caffeine and Cardiovascular Effects

  • NITI Aayog – Preventive Health and Lifestyle Modification Reports

  • Statista – Caffeine Consumption Trends in India

See all

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