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Immune Wellness

Getting Sick Often: Frequent Infections and "Low Immunity"

Getting several colds in a year is very common, and most of the time it does not mean your immune system is weak. This page helps you tell ordinary frequent colds from patterns that deserve a medical check, and what you can do in the meantime.

General information, not medical advice. Last updated October 31, 2026. Written by the AlternativeMed editorial team. Not medically reviewed.

Start here

  • Keep a short note of each illness: dates, symptoms, how long it lasted and whether you saw a clinician. A pattern is easier to judge on paper.
  • Wash hands with soap and water for about 20 seconds, cover coughs and sneezes, and aim for regular sleep.
  • Book a check if infections keep coming back, do not clear, or are unusually severe, and bring your list and any supplements you take.

Be careful with

  • "Low immunity" is a phrase used in everyday speech and on product labels, not a diagnosis. Be wary of any product that promises to fix it.
  • Antibiotics do not work on colds or flu, which are caused by viruses. Do not ask for them or take leftovers.
  • If you have an autoimmune condition, take medicines that lower immunity, or have had a transplant, ask your prescriber or pharmacist before any herb or supplement, and never stop a prescribed medicine on your own.

Get help when

  • Infections that keep coming back or do not go away, or a severe infection from germs that do not usually cause one.
  • Cold symptoms that are worse or no better after 10 days, a high temperature lasting more than 3 days, or a cough lasting more than 3 weeks.
  • Often getting sore throats (the NHS advises seeing a GP).
  • Any cold, flu or sore throat symptoms if you have a long-term condition or a weakened immune system, including from chemotherapy or steroid medicine.
  • Emergency: sudden chest pain, severe difficulty breathing or coughing up blood. The NHS says to call 999 in the UK; use your local emergency number (911 in the US).

About Getting Sick Often: Frequent Infections and "Low Immunity"

What this goal means

This goal is about understanding why you seem to get sick often: how many illnesses are typical, what could be making them more frequent, and which patterns call for a medical check. It is not about boosting the immune system, which has its own page, or about recovering from an illness you have now.

1

What it can feel like

Many people describe feeling run-down, catching whatever is going around, or never quite recovering before the next bug arrives. That feeling is real, but by itself it does not tell you what is going on.

2

What is normal

Adults average about 2 to 3 colds a year and children have more. More than 200 different viruses can cause a cold, so catching a new one is common. Symptoms can last 10 to 14 days, and the NHS says you should start to feel better in about 1 to 2 weeks. A run of colds in one season, especially with children at home or a busy workplace, is often within the normal range.

2,3

What can make illness more frequent

Colds spread through the air, through close contact and by touching surfaces then your eyes, mouth or nose, so exposure matters. In an experiment with 164 healthy adults exposed to a cold virus, those sleeping under 5 hours or 5 to 6 hours a night were more likely to develop a cold than those sleeping over 7 hours. Smoking can make cold symptoms worse. Illnesses can also be mixed up: hay fever can last weeks or months, while a cold usually passes in 1 to 2 weeks. Some conditions and medicines weaken the immune system too.

2,4,3,5

Conditions that can be behind it

Immunodeficiency diseases are conditions where the immune response is reduced or absent. Some are inherited. Others are acquired, for example through HIV, malnutrition (especially not eating enough protein), many cancers, removal of the spleen, ageing, or medicines such as corticosteroids and chemotherapy. Diabetes also raises the risk of certain infections. Allergies can also mimic repeated colds.

6,1

Realistic expectations

Habits such as sleep and hand washing may lower your chances of catching some infections, but no habit or supplement makes you immune to colds. If a pattern is unusual, the useful next step is a clinician's assessment, not a new product.

3,4

Who this applies to

Adults and parents wondering whether frequent illness is normal. Babies, older adults, pregnant people and anyone with a long-term condition or weakened immune system should seek advice earlier. This page cannot tell you which situation applies to you.

7

Related conditions and symptoms

Immunodeficiency, autoimmune conditions and immunosuppression → Allergies vs colds → Anemia and iron deficiency → Vitamin B12 deficiency → Sleep apnea → Prediabetes, type 2 diabetes and metabolic syndrome →

A manageable starting plan

An educational starting point, not a personal prescription. Adjust it to your own situation and any advice from your clinician.

Your first actions

  • Start an illness log for the next few months.
  • Protect your sleep, wash hands properly and stay home when contagious.
  • Check your vaccines with a clinician or pharmacist.
  • Book a check if infections keep coming back, do not clear or are severe.

Optional additions

  • Ask whether allergies could explain long-lasting symptoms.
  • Bring a list of your supplements to your appointment.
  • Ask a pharmacist about anything you take if you have a long-term condition.

What to track

  • Dates, length and severity of each illness.
  • Temperature and any antibiotics prescribed.
  • Sleep hours and exposure (children, workplace).
  • Any weight loss, night sweats or unusual tiredness to mention.

When to reassess

After a few months of notes, or sooner if illnesses worsen, take your log to a clinician.

When to seek professional support

  • A GP or primary care clinician is the first stop.
  • Ask your pharmacist about interactions before starting any supplement.

What helps

Ordered by how well the research supports each step. Evidence strength is shown on every card; precautions sit next to the advice.

Start here

Keep an illness log

Moderate certainty

Addresses: Helps you and a clinician see whether the pattern is ordinary

Why it may help: Because 2 to 3 colds a year is typical for adults, the question is usually whether yours are more frequent, longer, or more severe than that. A clinician may consider an immune problem when infections keep coming back or do not go away, when a severe infection comes from germs that do not usually cause one, when treatment response is poor, or when recovery is delayed or incomplete.

How to apply it: Note the start date, symptoms, temperature, how many days you were ill, whether you saw a clinician or were prescribed anything, and any exposure (children at home, workplace outbreaks, travel).

Who it may suit: Anyone who feels they are sick all the time.

Precautions: This is a record for discussion, not a way to diagnose yourself.

2,6

Wash your hands properly

Moderate certainty

Addresses: Reduces spread of germs

Why it may help: Cold viruses spread by touching a contaminated surface and then your eyes, mouth or nose, and the NHS notes germs can survive on hands and surfaces for up to 24 hours. The NHS advises scrubbing with soap for about 20 seconds, and washing after coughing or sneezing, after the toilet and before eating or preparing food. It recommends an alcohol-based sanitiser if soap and water are not available.

How to apply it: Wet, soap all surfaces including thumbs and fingertips, rub for about 20 seconds, rinse, dry with a disposable towel.

Who it may suit: Everyone, particularly in homes with children or at work.

Precautions: Frequent washing can dry skin; use a moisturiser if needed.

8,3,2

Cover coughs and sneezes, and stay home when you are contagious

Moderate certainty

Addresses: Protects you and others

Why it may help: The NHS says you are contagious until all symptoms have gone, usually 1 to 2 weeks. It advises covering coughs and sneezes with tissues and binning used tissues promptly. Passing colds around a household is one reason illness can seem constant.

How to apply it: Use a tissue, bin it straight away, wash hands, and avoid close contact with people at higher risk while you are ill.

Who it may suit: Households and workplaces with repeated illness.

Precautions: Take extra care around babies, older adults, and people with weakened immune systems.

3

Protect your sleep

Low certainty

Addresses: May lower your chance of catching a cold

Why it may help: In the Prather study, people sleeping under 5 hours or 5 to 6 hours were more likely to develop a cold after exposure to a cold virus than those sleeping over 7 hours (odds ratios of about 4.5 and 4.2). The study was observational in a small group of healthy adults, so it shows an association, not a guarantee.

How to apply it: Aim for a regular sleep schedule that leaves room for 7 or more hours.

Who it may suit: Adults who regularly short-change sleep.

Precautions: One study of 164 adults; sleep fragmentation was not linked to cold susceptibility in it.

4

Build a Healthy Sleep Schedule → Habits for immune health →

Stay away from smoke

Low certainty

Addresses: May ease cold symptoms

Why it may help: The NHS advises avoiding smoking because it can make cold symptoms worse.

How to apply it: If you smoke, ask a pharmacist or clinician for help quitting; avoid smoky rooms.

Who it may suit: Smokers and people in smoky homes.

Precautions: Do not stop a prescribed medicine to quit smoking without advice.

3

Additional options

Keep vaccines up to date

High certainty

Addresses: Helps prevent specific infections

Why it may help: The WHO explains vaccination trains the body to recognise specific germs. The NHS offers a flu vaccine to people at higher risk of serious illness, and your clinician can say which vaccines suit you, especially if your immune system is weakened.

How to apply it: Ask your clinician or pharmacist which vaccines you are due.

Who it may suit: Adults and children; particularly higher-risk groups.

Precautions: Vaccines for people with weakened immunity depend on the condition and treatment; ask your care team.

9,7

Vaccines and infection prevention →

Check whether it is allergy, not infection

Moderate certainty

Addresses: Avoids treating the wrong problem

Why it may help: Hay fever symptoms can last weeks or months and include itchy eyes, whereas a cold usually goes in 1 to 2 weeks. A pharmacist can suggest treatments for hay fever.

How to apply it: Note whether symptoms follow pollen, pets or dust, and whether you have a fever.

Who it may suit: People with long-lasting sniffles.

Precautions: This is not a diagnosis; see a clinician if unsure or symptoms worsen.

5,3

Allergies vs colds →

Ask for a check if the pattern fits

High certainty

Addresses: Finds treatable causes

Why it may help: Tests a clinician may use include immunoglobulin levels, white blood cell counts, T- and B-cell counts, HIV testing and checking responses to vaccines. A check can also look for other causes, such as diabetes or nutritional problems.

How to apply it: Bring your illness log and a list of medicines and supplements.

Who it may suit: Anyone with recurring, persistent or unusually severe infections.

Precautions: Do not try to interpret tests alone.

6

Immunodeficiency, autoimmune conditions and immunosuppression →

Food & nutrition

Food and frequent illness

MedlinePlus lists malnutrition, especially not eating enough protein, as one cause of weakened immunity that is not inherited. Regular, varied meals that cover your needs matter more than any single food; if you suspect you are not eating enough, or have lost weight without trying, speak to a clinician. We did not find a food that has been shown to stop frequent colds.

The NHS says there is little evidence that vitamin C, echinacea or garlic prevent colds.

6,3

Remedies & supplements

Traditional use, laboratory findings and human trials are kept apart. "Natural" does not mean safe.

Vitamin C, echinacea and garlic

Low certainty

Studied form and route: Supplements

Intended outcome: Preventing colds or speeding recovery

Human evidence: The NHS says there is little evidence that these prevent colds or help you get better faster.

Traditional use: Widely used traditionally and in marketing for colds and "immune support".

Laboratory findings: We did not find lab data relevant to frequent illness in the sources we read.

Limits: We did not find evidence that any supplement fixes frequent infections.

Interactions and precautions: Echinacea belongs to the daisy family and can cause allergy; garlic supplements may increase bleeding risk; supplements can interact with medicines, including immune-lowering medicines. Check with a pharmacist, and in pregnancy or for children ask a clinician.

3

Vitamin C, vitamin D and zinc → Echinacea, elderberry, garlic and mushrooms → Immune safety →

Therapies & care

Established care starts with a clinician looking at your history and, where needed, tests. Treatment depends on the cause. This page does not recommend medicines or doses, and you should not stop a prescribed medicine on your own.

Clinical assessment of recurrent infections

High certainty

Medical evaluation A clinician may ask about infections that keep coming back or do not go away, severe infections, response to treatment and recovery, and may arrange blood tests such as immunoglobulin levels, white blood cell counts, T- and B-cell counts and HIV testing, or check your response to vaccines.

Who it may suit: People with recurring, persistent or unusually severe infections.

Precautions: Results need professional interpretation.

6

Immunodeficiency, autoimmune conditions and immunosuppression →

Seeing a GP for repeated sore throats

Moderate certainty

Primary care The NHS advises seeing a GP if you often get sore throats. Antibiotics are not normally needed for sore throat and are only prescribed if a bacterial infection is possible.

Who it may suit: People with frequent sore throats.

Precautions: Difficulty breathing, inability to swallow, or drooling is an emergency.

10

Cough and sore throat remedies →

What to avoid

Habits, products and claims that can get in the way. Never stop a prescribed medicine without talking to the professional who prescribed it.

Risks that apply to most people

Assuming frequent colds mean a weak immune system

High certainty

Why: Several colds a year are normal. MedlinePlus describes immunodeficiency as a reduced or absent immune response, and the pattern includes infections that keep coming back, do not clear, or are unusually severe.

Who it applies to: Anyone worried about low immunity.

Try instead: Keep a log and ask a clinician if the pattern is unusual.

2,6

Asking for antibiotics for colds or flu

High certainty

Why: Colds and flu are viral and antibiotics do not work on them; the NHS says GPs do not recommend them for colds.

Who it applies to: Anyone with a cold, flu or sore throat.

Try instead: Rest, fluids and pain relief as advised by a pharmacist; see a clinician if worse.

3,7,10

Going to work or school while contagious

Moderate certainty

Why: The NHS says you are contagious until all symptoms have gone, which is usually 1 to 2 weeks.

Who it applies to: Households and workplaces with repeated illness.

Try instead: Stay home when you can and wash hands often.

3

Personal triggers to check

Short sleep

Low certainty

Why: In one study people sleeping under 6 hours were more likely to get a cold after exposure than those sleeping over 7.

Who it applies to: Adults who sleep little.

Try instead: Protect a regular sleep window.

4

Smoking

Moderate certainty

Why: The NHS says smoking can make cold symptoms worse.

Who it applies to: Smokers.

Try instead: Seek support to quit; avoid smoke.

3

Heavy alcohol use

Low certainty

Why: A review of alcohol's effect on host defence reports effects on immune function.

Who it applies to: Heavy drinkers.

Try instead: Keep alcohol low; ask a clinician if you find it hard to cut down.

11

Habits for immune health →

Products that need caution

Immune supplements as a fix for frequent colds

Low certainty

Why: The NHS says there is little evidence that vitamin C, echinacea or garlic prevent colds or help you get better faster. Some herbs may interact with immune-related medicines.

Who it applies to: People tempted by "immune boosting" products.

Try instead: Tell a pharmacist about everything you take.

3

Vitamin C, vitamin D and zinc → Echinacea, elderberry, garlic and mushrooms →

Unsupported claims

"Boosts immunity" claims

Low certainty

Why: A healthy immune system is not a single dial you can turn up, and "immune boosting" is a poor fit when the immune system is overactive, as in autoimmune disease.

Who it applies to: Product labels and ads.

Try instead: Treat the claim as marketing and ask a clinician.

1

How the immune system works →

Common mistakes

Waiting too long when red flags appear

High certainty

Why: The NHS lists a high temperature for more than 3 days, symptoms that worsen, shortness of breath or chest pain, no improvement after 10 days, and a cough over 3 weeks as reasons to see a GP.

Who it applies to: Anyone with a long illness.

Try instead: Contact a clinician earlier if you have a long-term condition or weakened immune system.

3

Evidence & safety

What the research shows

Health agencies agree that a few colds a year is normal and that antibiotics do not treat viral infections. Patterns that may suggest an immune problem are infections that keep coming back or do not clear, severe infections from unusual germs, and poor response to treatment. Short sleep was linked to colds in one small study. Supplements have little supporting evidence for preventing colds.

Limits of the evidence

  • The sleep study was observational and small.
  • We did not find trials showing that any supplement lowers frequent infections.
  • This page cannot tell which situation applies to you.

Precautions and interactions

  • Check supplements with a pharmacist if you take any medicine, especially immune-lowering medicines.
  • Never stop a prescribed medicine because of a product claim.
  • Do not give aspirin to children for cold or flu.

Life-stage considerations

  • Children get more colds than adults.
  • Pregnancy and breastfeeding: ask a clinician before any supplement.
  • Older adults and people 65 or over: the NHS advises urgent advice for flu symptoms.
  • People with a weakened immune system: contact your care team early with any infection symptoms.

Warning signs

  • Infections that keep coming back or do not go away.
  • High temperature for more than 3 days, symptoms that worsen, or no improvement after 10 days.
  • Fever of 38C (100.5F) or higher with chemotherapy or steroid medicine.
  • Stiff neck with headache and fever: emergency care.
  • Sudden chest pain, severe difficulty breathing or coughing up blood: call your local emergency number.

Claim checks

Frequent colds mean I have low immunity

Not necessarily

2,6

Vitamin C, echinacea or garlic prevent colds

Little evidence

3

Antibiotics help with colds

False

2,3

Questions people ask

How many colds a year are normal?

MedlinePlus says adults average 2 to 3 colds a year and children have even more.

Does getting sick often mean I have a weak immune system?

Not necessarily. Immunodeficiency involves infections that keep coming back, are unusually severe, or do not clear. A clinician can assess this.

Can a blood test show whether my immunity is low?

Clinicians may check immunoglobulin levels, white blood cell counts, T- and B-cell counts and responses to vaccines when they suspect an immunodeficiency.

Will vitamins fix frequent colds?

The NHS says there is little evidence that vitamin C, echinacea or garlic prevent colds or help you get better faster.

How long should a cold last?

Symptoms can last 10 to 14 days; the NHS says to see a GP if there is no improvement after 10 days.

Do antibiotics help colds?

No. Colds are caused by viruses, and antibiotics only work against bacteria.

Does lack of sleep make colds more likely?

One study of 164 healthy adults found people sleeping under 6 hours were more likely to develop a cold after virus exposure than those sleeping over 7 hours. It shows an association.

Could it be allergies instead?

Possibly. Hay fever can last weeks or months, while a cold usually passes in 1 to 2 weeks.

When should I see a doctor about repeated sore throats?

The NHS says to see a GP if you often get sore throats.

I take medicines that lower immunity. What should I do when I feel ill?

Contact your care team early; for example, MedlinePlus advises prompt contact for fever of 38C (100.5F) or higher on chemotherapy or steroids. Do not stop prescribed medicines on your own.

References

  1. MedlinePlus (U.S. National Library of Medicine). Immune System and Disorders. Read 2026-10-22. source
  2. MedlinePlus (U.S. National Library of Medicine). Common Cold. Read 2026-10-31. source
  3. NHS. Common cold. Read 2026-10-31. source
  4. Prather AA, et al. Behaviorally assessed sleep and susceptibility to the common cold. Sleep. 2015;38(9):1353-9. PubMed record read 2026-10-31. source
  5. NHS. Hay fever. Read 2026-10-22. source
  6. MedlinePlus Medical Encyclopedia. Immunodeficiency disorders. Read 2026-10-31. source
  7. NHS. Flu. Read 2026-10-31. source
  8. NHS. How to wash your hands. Read 2026-10-31. source
  9. World Health Organization. Vaccines and immunization: What is vaccination? (22 October 2025). Read 2026-10-22. source
  10. NHS. Sore throat. Read 2026-10-31. source
  11. Szabo G, Saha B. Alcohol's effect on host defense. Alcohol Res. 2015. PubMed record read 2026-10-22. source

Related on AlternativeMed

Related goals

Support Normal Immune Function → Build Everyday Immune-Supportive Habits → Meet Your Nutritional Needs for Immune Health → Prepare for Cold & Flu Season → Reduce Your Risk of Common Infections → Support Recovery From Common Illness → Return to Your Routine After Illness →

Ingredients, foods and supplements

Echinacea, elderberry, garlic and mushrooms → Vitamin C, vitamin D and zinc →

Research, safety and claim-check resources

Immune safety and when to get help → Immune research and evidence → How the immune system works → Cough and sore throat remedies → Talking with a health professional → Immune Wellness →