• Published on: Apr 30, 2022
  • 2 minute read
  • By: Second Medic Expert

What Is PET Scan ?

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A PET scan (positron emission tomography) is a type of imaging test that uses a radioactive tracer to look for changes in the function of cells and tissues. A tracer is a substance that is introduced into the body to make it easier to see certain areas or organs. The radioactive tracer used in PET scans emits positrons, which are tiny particles that collide with electrons in the body. This creates gamma rays that can be detected by a scanner and used to create images of the inside of the body. PET scans are often used to diagnose cancer because tumor cells typically have higher levels of activity than normal cells. They can also be used to check for treatment response, measure tumor size, and identify new tumors.

PET Scan is a nuclear medicine imaging test that uses a small amount of radioactive material, called a tracer, to look for disease in the body. A PET Scan can show how well organs and tissues are working. It can help find cancer, heart problems, and other diseases. A Positron Emission Tomography (PET) scan is a medical imaging test that helps physicians diagnose and treat diseases. PET scans use a small amount of radioactive material, called a tracer, to help physicians see how organs and tissues are functioning. The radioactive tracer is injected into the patient's body and travels to the organ or tissue being studied. Physicians can then see where the tracer collects on an image of the organ or tissue.

A PET scan is helpful in diagnosing cancer, heart disease, brain disorders, and other diseases. It can also help determine how well treatment is working. PET Scan is an acronym for Positron Emission Tomography. It's a type of medical imaging that uses a small amount of radioactive material to help diagnose and treat medical conditions. A PET scanner creates 3D images of the inside of the body. PET (positron emission tomography) scans use a small amount of radioactive material called a tracer to help doctors see certain areas of the body. The tracer is injected into a vein, and images are taken as it moves through the body.

PET scans are often used to find cancer because tumors absorb more of the radioactive material than normal tissue does. PET scans can also be used to measure blood flow, check how well drugs work, and see how active the brain is. A PET scan is a type of imaging test that uses radioactive tracers to look at the function and structure of organs and tissues in your body. A small amount of radioactive material is injected into your bloodstream and then scanned by a special camera. The camera creates pictures that show where the material has collected. This can help doctors see how well an organ is working or find tumors or other problems.

PET scan is short for positron emission tomography. It's a type of medical imaging that uses a radioactive tracer to look at organ function or tissue metabolism. The tracer is a small amount of radioactive material that's injected into the patient's bloodstream. It collects in organs and tissues, and a scanner detects the radiation emitted as it decays. This information is used to create cross-sectional images of the body that show how the organs and tissues are working. PET scans are most often used to detect cancer because tumors consume more energy than normal tissue and therefore have a higher metabolic rate. But they can also be used to evaluate other problems, such as heart disease, brain function, and joint damage.

PET scanning is a type of nuclear medicine imaging. A small amount of radioactive glucose (FDG) is injected into a vein and images are taken as the glucose moves through the body. Cancer cells use more energy than normal cells and therefore absorb more of the radioactive glucose. This allows tumors to be visualized on the scan. PET stands for Positron Emission Tomography. A PET scan is a medical imaging test that uses a radioactive tracer to look at organs and tissues inside the body. The tracer is injected into a vein, and images are taken as it moves through the body.

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sleep

How Lack of Sleep Weakens Immunity: Why Poor Sleep Makes You Fall Sick More Often

Sleep is one of the most powerful yet overlooked pillars of health. While nutrition and exercise receive significant attention, sleep often takes a back seat in modern lifestyles. Understanding how lack of sleep weakens immunity reveals why people who sleep poorly fall sick more often, take longer to recover and experience chronic inflammation.

In India, late-night work culture, excessive screen time and irregular schedules have made sleep deprivation increasingly common across age groups.

 

The Link Between Sleep and the Immune System

The immune system relies on sleep for:

  • repair and regeneration

  • immune cell production

  • inflammation control

During deep sleep, the body releases cytokines and antibodies that protect against infections.

 

What Happens to Immunity During Sleep

While sleeping:

  • immune cells identify pathogens

  • inflammatory responses are regulated

  • memory T-cells strengthen immune memory

This nightly process prepares the body to fight infections effectively.

 

How Sleep Deprivation Disrupts Immune Function

When sleep is inadequate:

  • immune cell activity decreases

  • antibody production drops

  • inflammation increases

WHO studies confirm that sleep deprivation weakens immune defence mechanisms.

 

Increased Risk of Infections

People who sleep less than 6 hours regularly:

  • fall sick more often

  • catch colds and flu easily

  • recover slower from illness

Lancet research shows a strong link between sleep duration and infection susceptibility.

 

Impact on Inflammation

Poor sleep increases inflammatory markers.

Chronic inflammation:

  • weakens immune response

  • increases risk of chronic diseases

ICMR reports highlight sleep deprivation as a contributor to low-grade systemic inflammation.

 

Effect on Vaccine Response

Sleep quality affects how well vaccines work.

Studies show:

  • poor sleep reduces antibody response

  • adequate sleep improves vaccine effectiveness

Sleep is essential for immune memory formation.

 

Hormonal Changes That Affect Immunity

Sleep regulates hormones such as:

  • cortisol

  • melatonin

Lack of sleep increases cortisol, which suppresses immune function.

 

Stress, Sleep and Immunity

Sleep deprivation and stress reinforce each other.

High stress:

  • disrupts sleep

  • suppresses immune cells

This cycle weakens overall resistance to illness.

 

Impact on Gut Immunity

The gut hosts a major part of the immune system.

Poor sleep:

  • disrupts gut microbiome

  • weakens gut immunity

Lancet studies link sleep deprivation to gut-related immune dysfunction.

 

Why Children and Older Adults Are More Vulnerable

Sleep deprivation affects:

  • children’s developing immune systems

  • older adults’ already weakened immunity

Adequate sleep is especially important in these age groups.

 

Signs Your Immunity Is Affected by Poor Sleep

Warning signs include:

  • frequent infections

  • slow wound healing

  • constant fatigue

  • increased allergies

These symptoms indicate compromised immune defence.

 

Long-Term Health Risks of Poor Sleep

Chronic sleep deprivation increases risk of:

  • infections

  • autoimmune disorders

  • metabolic diseases

  • heart disease

Sleep loss affects nearly every body system.

 

Role of Preventive Health Awareness

Preventive healthcare emphasises:

  • sleep as a foundation of immunity

  • early lifestyle correction

NITI Aayog recognises sleep hygiene as essential for population health.

 

How to Improve Sleep for Better Immunity

Effective strategies include:

  • fixed sleep and wake times

  • limiting screen exposure before bed

  • avoiding caffeine late in the day

  • creating a dark, quiet sleep environment

Consistency matters more than duration alone.

 

Myths About Sleep and Immunity

Myth: You can catch up on sleep later
Fact: Chronic sleep debt harms immunity.

Myth: Sleeping pills improve immunity
Fact: Natural sleep is more beneficial.

 

Why Sleep Is a Preventive Medicine

Sleep:

  • costs nothing

  • requires no equipment

  • delivers powerful immune protection

It is one of the most effective preventive health tools.

 

Conclusion

Understanding how lack of sleep weakens immunity highlights the critical role of sleep in protecting the body from infections and chronic disease. Poor sleep disrupts immune cell function, increases inflammation and reduces resistance to illness. Prioritising consistent, quality sleep is not optional—it is essential for strong immunity, faster recovery and long-term health. Protecting sleep today strengthens immune defence for tomorrow.

 

References

  • Indian Council of Medical Research (ICMR) – Sleep, Immunity and Inflammation Studies

  • World Health Organization (WHO) – Sleep and Immune Health Guidelines

  • National Institutes of Health – Sleep Deprivation and Immunity

  • Lancet – Sleep Duration and Infection Risk

  • NITI Aayog – Preventive Health and Lifestyle Recommendations

See all

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