Preparing For The Cold And Flu Season

Learn how to prepare for the cold and flu season by understanding the scientific mechanisms behind these conditions in our expert guide.

Updated: Wednesday 04 October 2023

Flu Season

When the NHS began its flu vaccination campaign at the beginning of September 2023, almost 4 million people signed up to receive a jab in a matter of weeks,[1] signifying the impending arrival of the cold and flu season.

People often begin to prepare for the cold and flu season when the weather gets colder and children return to schools where there’s a substantial risk of contracting seasonal infectious diseases.[2]

Although vaccinations are important to safeguard against cold and flu, there are several additional steps our pharmacy team recommends to bolster the body’s defences against these conditions - and that’s the purpose of this guide.

Read on to learn how to best prepare for the cold and flu season based on our experts’ review of the latest scientific research.

When is the cold and flu season?

The cold and flu season can occur anytime from the beginning of autumn to spring. It tends to peak between December and March when seasonal flu transmissions are at their highest due to factors like exceptionally cold weather impacting our immune systems in the winter.[3]

Cold vs flu


According to the latest research,[4] colds can be caused by over 200 types of viruses. Many of these viruses are classified as ‘rhinoviruses’ because they primarily infect the nose (‘rhin’ is the Greek word for the nose).[5] In contrast, the flu can only be caused by one type of virus known as influenza.

Rhinoviruses and influenza viruses affect the body via the same mechanism. They enter the body through respiratory tracts before injecting their genetic material into cells to infect them. This causes the viral genome to be replicated, resulting in new virus particles that can infect other cells.[6]


Cold and flu symptoms are similar but not identical. Our experts have summarised key cold and flu symptoms and their likelihood of occurring in the table below.

Symptoms Likelihood of the symptom occurring with a cold Likelihood of the symptom occurring with the flu
Stuffy nose High Occasional
Sore throat High Occasional
Headache Occasional High
Fever Low High
Aches Occasional High
Chills Low High
Fatigue (Body weakness) Occasional High
Sneezing High Occasional
Coughing and chest discomfort High (but often mild) High (potentially severe)

Flu symptoms tend to be worse than cold symptoms and begin more abruptly. In many cases, the flu is accompanied by a fever which can cause chills, headaches, and a raised temperature.

Our pharmacy team recommends keeping a digital thermometer or infrared thermometer handy to get an accurate temperature reading. This can help with differentiating between whether someone has contracted the cold or flu.

It’s important to remember that the common cold does not typically pose any serious health risks. In contrast, the flu can sometimes cause complications such as sinus infections, ear infections, and/or pneumonia.

The following flu symptoms can indicate additional health complications. We recommend contacting a medical professional immediately if you experience these symptoms:

  • Difficulty breathing
  • Persistent chest and/or abdominal pain
  • Severe muscle pain
  • Persistent dizziness


As we touched on earlier in this guide, the influenza virus that causes the flu consists of 8 RNA segments compared to the single RNA strand within viruses that cause colds such as rhinoviruses.

This makes the influenza virus capable of mutating quicker than rhinoviruses because multiple RNA segments can be rearranged to create new strains of influenza as compared to other types of viruses.


The terms ‘common cold’ and ‘seasonal flu’ are often used to describe the cold and flu because of the perception that the former occurs year-round while the latter only occurs during the colder seasons (please refer to our ultimate guide to cold and flu for more information).

While it is true that both the cold and flu can be caught year-round, there is empirical evidence to suggest that the flu is more likely to be seasonal due to the mechanisms of two key factors. These are outlined below:

Factor Mechanism
Drop in air temperature According to some studies,[7] a drop in air temperature can affect the production of inflammatory cytokines in the body. This can reduce the immune system’s defences against the influenza virus responsible for the flu.
Drop in air humidity Researchers recently discovered[8] that when compared to inhaling through the mouth, inhaling through the nose can trigger the release of extracellular vesicles that attack bacteria present in the inhaled air.
A drop in air humidity during the colder months can dry out the lining of the nose. This can make it uncomfortable to breathe in through the nose, making it more likely for viruses to enter the body through the mouth unscathed.

Key steps to prepare for the cold and flu season

Step 1: Get vaccinated

Vaccination is one of the most important defences against cold and flu. Research shows that flu vaccines can reduce the risk of hospitalisation from severe flu symptoms by 40% in adults[9] and by up to 75% in children.[10]

Flu vaccines are typically available through private providers. The NHS has also made flu vaccinations available at no cost to individuals who belong to one or more of ten categories of people deemed to be at an increased risk from flu3.

Step 2: Stock treatments for cold and flu


Some decongestants such as phenylephrine (a key ingredient in Lemsip Max capsules and Lemsip Max sachets) can reduce inflammation and swelling in the nasal passages by narrowing blood vessels in the nose.[11] This helps relieve some cold and flu symptoms such as a stuffy nose.

Please note that some decongestants are unsuitable for people who have heart conditions such as high blood pressure. Our pharmacy team recommends topical ointments such as Vicks VapoRub to clear nasal passages and sinuses as an alternative to decongestants for those who are unable to take them.

Cough syrups

Coughing is a natural reflex that helps with clearing mucus from the airways. As we touched on previously in this article, severe bouts of coughing and chest discomfort are more likely to affect those who contract the flu and can be relieved using cough syrups.

Chesty cough syrups are recommended for those who have a mucus build-up as they can loosen phlegm, making it easier to cough up. On the other hand, for those who experience recurring coughs, dry and tickly cough syrups can be used to suppress the cough by stopping the brain from sending signals to trigger the cough reflex.

We recommend speaking with a pharmacist or GP before taking any type of cough syrup.

Antiviral treatments

Antiviral treatments can shorten the duration of the flu by preventing the influenza virus from replicating in the body. Some antiviral treatments such as Tamiflu are available to individuals who pass a medical assessment and can be especially effective when used alongside personal protective equipment (PPE) such as face masks for flu prevention

Please be advised that antiviral treatments are not suitable to treat the common cold.

Pain relief treatments

Pain relief treatments can be effective at reducing head and body aches associated with colds and flu.

The table below summarises four effective pain relief treatments for cold and flu as well as their mechanisms and the symptoms they can help relieve. Please consult a pharmacist or GP before taking any of the treatments below.

Active Ingredient/Treatment Mechanism Primary symptom(s) relieved
Paracetamol (available on its own at Pharmica or as part of Lemsip Max capsules/sachets) The exact mechanism of action for paracetamol is still being researched.
Some studies[12] suggest that paracetamol may inhibit COX enzymes that convert arachidonic acid to prostaglandin (a chemical that plays an important role in inflammation and pain). However, paracetamol does not have anti-inflammatory effects.
There is also research[13] to suggest that paracetamol can affect several pain pathways in the brain.
Headache, body ache, fatigue, chills
Ibuprofen (available on its own at Pharmica) Ibuprofen inhibits COX enzymes so they stop producing inflammatory prostaglandins. This is why ibuprofen is classified as an NSAID (a non-steroidal anti-inflammatory drug). Headache, body ache, fatigue, chills
Phenylephrine (part of Lemsip Max capsules/sachets) Phenylephrine reduces nasal swelling by narrowing blood vessels in the nose.[14] Stuffy nose, sore throat
Antihistamine (part of Lemsip Max capsules/sachets) Stops sneezing by preventing the release of a chemical called histamine (histamine is typically released in response to allergens).[15] Sneezing, stuffy nose

Step 3: Boost immunity through nutritional supplements

Certain vitamins can help with preparing for the cold and flu season by bolstering the body’s natural immunity and reducing inflammation.

Our Pharmacists recommend the following three vitamins to help protect against cold and flu symptoms as their efficacy is backed by recent scientific research.[16],[17]

  1. Vitamin C (from citrus fruits) can increase the production of white blood cells and antibodies to fight off cold and flu viruses.
  2. Vitamin D (from sun exposure) increases the production of antimicrobial peptides that can kill viruses that cause the cold and flu.
  3. Zinc (from certain foods such as meat, chickpeas, or almonds) can help reduce inflammation by inhibiting the production of pro-inflammatory cytokines in the body.

Step 4: Follow a sleep schedule

According to multiple studies,[18],[19] adequate daily sleep can increase the body’s production of T cells and counter pro-inflammatory signalling in the body. Both these mechanisms can help reduce the probability of being infected with cold and flu viruses.

It’s also important to consider sleep timings. Going to bed and waking up at the same time every day can help regulate physical, mental, and behavioural changes following a 24-hour day and night cycle (known as the circadian rhythm). This can subsequently help with regulating the secretion of proinflammatory cytokines that affect the immune system.[20]

Therefore, following a sleep schedule that allows for 6-8 hours of high-quality sleep every night can help prepare the body for the cold and flu season ahead.

Recommended reading: Complete guide to sleeping better at night.

Preparing for a super cold

What is a super cold?

The term ‘super cold’ first gained traction after the peak of COVID-19 in 2021. At the time, an article by the BBC[21] described the super cold as ‘the worst cold ever’ because of the severity of symptoms such as excessive fatigue, a heavy and frequent cough, and a constantly runny nose.

Symptoms of a super cold

The symptoms of a super cold are identical to those of a cold (even though they can be more severe). Therefore, it is recommended to prepare for a super cold in the same way you would prepare for the cold and flu season.

Super cold treatments

The symptoms of a super cold can be relieved using the same treatments that are typically recommended for those with a common cold. Please consult a pharmacist or GP about suitable treatments and dosage strengths.

Stock treatments now to prepare for the cold and flu season

Our team of experts at Pharmica help countless people prepare for the cold and flu season each year. We offer MHRA-approved cold and flu treatments that can help relieve symptoms effectively and we deliver to home and work addresses for maximum convenience.

We also provide health and lifestyle advice based on the latest research through our Health Centre on an array of additional conditions, including weight loss, erectile dysfunction, and more.

With a 4.9 out of 5 rating from over 160,000 reviews and over a million patients served, we’re proudly transforming the digital pharmacy experience in the UK.

Browse our full range of treatments today.

  1. England. National Health Service. Millions can book flu jabs online from Monday.
  2. Donaldson et al. 2020. Risk factors associated with outbreaks of seasonal infectious disease in school settings, England, UK.
  3. NHS. 2023. The flu vaccination - who should have it and why (winter 2023 to 2024).
  4. Harvard Health Publishing. 2023. Common cold (viral rhinitis).
  5. Centers for Disease Control and Prevention. n.d. Rhinoviruses.
  6. Zhu et al. 2022. A structural understanding of influenza virus genome replication.
  7. Castellani et al. 2002. Cold exposure: human immune responses and intracellular cytokine expression.
  8. Harvard Medical School. 2022. Why upper respiratory infections are more common in colder temperatures
  9. McLean et al. 2023. Interim estimates of 2022–23 seasonal influenza vaccine effectiveness — Wisconsin, October 2022–February 2023.
  10. Olson et al. 2022. Vaccine effectiveness against life-threatening influenza illness in us children.
  11. Stanford Medicine. n.d. Eustachian tube dysfunction.
  12. Ayoub 2021. Paracetamol (acetaminophen): A familiar drug with an unexplained mechanism of action.
  13. Sharma & Mehta. 2013. Paracetamol: mechanisms and updates.
  14. Medline Plus. n.d. Phenylephrine.
  15. NHS. n.d. Antihistamines.
  16. Moore and Khanna. 2022. The role of vitamin C in human immunity and its treatment potential against COVID-19: A review article.
  17. Zhu et al. 2022. Association between vitamin D and influenza: meta-analysis and systematic review of randomized controlled trials.
  18. UC Health. 2020. Creating better sleep habits to strengthen immunity.
  19. Garbarino et al. 2021. Role of sleep deprivation in immune-related disease risk and outcomes.
  20. Haspel et al. 2020. Perfect timing: circadian rhythms, sleep, and immunity — an NIH workshop summary.
  21. BBC. 2021. Super cold: Is 'the worst cold ever' going around?
Kamran Bell

Written by: Kamran Bell

Pharmacist・GPHC Number 2231070

Kamran graduated with a four-year master's degree in pharmacy from Aston University in 2021. He completed a pre-registration year at a community pharmacy before working there for a further year. At Pharmica, Kamran provides expert patient advice and addresses clinical questions to ensure the health and well-being of our patients.

Carolina Goncalves

Medically Reviewed by: Carolina Goncalves

Superintendent Pharmacist・GPHC Number 2088658

Carolina Goncalves is the Superintendent Pharmacist at Pharmica, where she ensures patients receive exceptional healthcare and support, as part of a seamless online pharmacy service.

With a comprehensive professional background spanning more than 13 years, Carolina has extensive experience supporting Men’s and Women’s health. Carolina is responsible for providing expert treatment advice to thousands of patients in areas such as Sexual Health, Erectile Dysfunction, Hair Loss, Weight Loss and Asthma.

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The Ultimate Guide To Cold & Flu
The Ultimate Guide To Cold & Flu