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Published on: Jul 09, 2020
2 minute read
By: Dr Rakesh Choudhary

COVID- 19 Tests – What Do You Need To Know?

COVID- 19 tests – What do you need to know?

Author: Dr. Rakesh Choudhary MBBS, MS, FRCS UK, FRCS Orth UK, MChOrth UK.

Dr. Choudhary is a practicing consultant surgeon in the UK.

So many of us think it is not their job to learn about COVID-19 tests and this should be left for the experts and governments to decide about these tests. But I strongly suggest the public must have a basic understanding of these tests which they may have to have themselves.

Basically there are two types of tests, one which can detect the virus in the body and the other one which tells if the person had the previous infection.

Virus test

The virus test detects an active infection. It detects the genetic material (RNA) of the virus during an active infection. It is also called a PCR (polymerase chain reaction) test or nucleic acid test and is sometimes inaccurately called an antigen test.

A swab is taken from deep in the back of your throat and deep in the nose. The swab should go deep up to 7-8 cm and is generally uncomfortable for the patient. Swabbing patients using the correct technique is paramount in ensuring an accurate result. By simply swabbing the inside of the nasal passage is not deep enough to verify that the virus is present.

What does virus testing tell you?

This test tells us if a patient is actively infected with the COVID-19 virus. Virus testing is used mainly for the diagnosis of COVID-19.

When should it be done?

The virus test works best during the first seven days of symptoms.

The coronavirus can be detected in swabs even before symptoms of illness first appear . This is why people can be infectious for a few days before the onset of symptoms, which usually appear about 5 days after the virus infects. Some people have no symptoms throughout their infection but are positive on the virus test and infectious to others. After a few days of illness, the concentration of the virus falls (as seen in swab samples) and the symptoms of the illness usually recede.

Accuracy of the test

In a person with COVID-19, the test is less likely to give a positive result late in the course of infection once the virus has been cleared by the immune system, or if an inadequate sample is taken from the nose or throat. There are concerns that the rate of ‘false negative’ test results could be as high as 30% and a significant number of people are wrongly being told they do not have the virus.

Antibody test

Antibody tests check your blood by looking for antibodies, which may tell you if you had a past infection with the virus that causes COVID-19. Antibodies are protein structures that are produced by the immune system in response to certain infections. The antibody can help fight off infections and can provide protection against getting that disease again (immunity). Antibodies are disease-specific. For example, measles antibodies will protect you from getting measles if you are exposed to it.

The antibody test detects the presence of antibodies as a marker of past infection. The antibody test (blood test) will only detect infections after the immune system has produced antibodies that recognize the virus. This happens approximately 7–10 days after symptoms develop.

Tests carried out a week after a patient develops symptoms will detect only 30% of people who had COVID-19 infection. Accuracy increases to 72% at two weeks and to 94% in the third week. Some people may take even longer to develop antibodies, and some people who are infected may not ever develop antibodies.

Interpretation of the antibody test is complex for non-medical people. Basically having antibodies to the virus that causes COVID-19 may provide protection from getting infected with the virus again. If it does, we do not know how much protection the antibodies may provide or how long this protection may last.

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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

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