As parents, it’s natural to worry about how often our children get sick. Understanding the typical frequency of illnesses at different ages can help us feel at ease and better understand what to expect. This article provides a look at why children get sick, the development of the immune system, and what is considered normal in terms of illness frequency and severity. It also shares some insight on how we can support our children’s immune health.
Average Sickness Frequency by Age
Many parents express feeling worried about their young children getting sick too often. Once I share the averages with them, most parents instantly feel more at ease, and they are often surprised to learn that it is actually quite common for children to get sick multiple times per year.
Babies (0-12 months): On average, babies can get sick 6 to 12 times per year (1). This high frequency is due to their developing immune systems and initial exposure to various pathogens.
Preschoolers (1-5 years): Preschool-aged children typically experience 7 to 10 illnesses annually (1). Increased exposure to other children in daycare, preschool, or other social settings tends to lead to frequent colds and other infections during this time.
School-Aged Children (6-12 years): School-aged children get sick around 6 to 8 times per year (1). Their immune systems are stronger than those of younger children, but school environments provide ample opportunities for germ sharing.
Teenagers (13-18 years): Teenagers tend to fall ill 4 to 6 times per year (1), which is in line with averages for adults (1). Their more mature immune systems and better hygiene practices result in fewer illnesses compared to younger children.
Immune System Development
It is normal for sickness frequency to decrease as children age. This is, in part, because the immune system evolves significantly from infancy through adolescence.
Newborns and Infants
A newborn has an underdeveloped immune system that is still learning to recognize and combat pathogens (2). Newborns are born with antibodies passed from their mothers during pregnancy and, if breastfed, through breast milk (2). These antibodies provide initial protection against infections (2). Research shows that breastfed babies tend to get sick less often than formula-fed babies due to the presence of maternal antibodies in breast milk (3).
Babies born via vaginal birth are exposed to beneficial bacteria from the mother’s birth canal, which helps to populate their gut microbiome and strengthen their immune system (4). While babies born by c-section miss out on this initial exposure, frequent skin-to-skin contact and breastfeeding can help compensate for this difference. It is noteworthy that premature infants are more susceptible to infection (5). This is because they forgo a crucial period of immune development that typically occurs in the later stages of pregnancy (5). For premature babies, it is important to support their immune health through practices like breastfeeding and skin-to-skin contact, as well as closely monitoring and managing their exposure to potential infections.
Toddlers and Preschoolers
As children grow, their immune systems become more adept at recognizing and fighting pathogens. Increased interaction with other children in daycare, preschool, or other settings exposes young kids to a variety of germs, and the immune system “learns” or adapts from this exposure and gradually becomes more robust (6).
School-Aged Children
It is common for school aged children to get sick frequently; though by this age the frequency of illness is often notably less than during the preschool years (1). This is in part due to their maturing immune systems, as school aged children have been exposed to many common pathogens and have developed specific antibodies (6). Also, by this age, many kids are more likely to follow good hygiene practices, including covering sneezes and effective handwashing, reducing the spread of germs and as such the frequency of illness.
Teenagers and Adults
The teenaged immune system is on par with adults in terms of maturity. However, highschoolers tend to be in closer contact with their peers on a day to day basis compared to adults in the average workspace environment, so you may notice that your teen does tend to get sick slightly more often than you do.
Is “Normal” Optimal?
You may be wondering, although these frequencies of illness are considered normal, does that necessarily mean they are optimal? And that is a great question! I want to explain a little about why frequent illness during childhood is an integral part of immune system development, and why it’s not necessarily always better to get sick less frequently.
Childhood Illness & The Immune System
Illnesses during childhood play a role in developing a strong and resilient immune system (7). Here’s why:
Immune System Training
Each time a child gets sick, their immune system learns to recognize and fight off the pathogen responsible for the illness (8). This process helps build a memory bank of antibodies, making the immune system more efficient at responding to future infections. The immune system’s ability to remember and respond to specific pathogens is called adaptive immunity (8), and this is partly why older children and adults tend to get sick less often and recover more quickly (8).
Interestingly, there is some evidence that early and frequent exposure to a range of pathogens helps maintain a balanced immune system, potentially reducing the risk of overreactions such as allergies and autoimmune diseases (9). There is even a study that shows that children who go to daycare as infants (and thus are exposed to more germs from a young age) are less likely to get ALL (acute lymphoblastic leukemia) in their lifetime (10). This is not to say that you need to go overboard and forego handwashing all together, but it is to say that normal exposure to social situations and refraining from over-sanitization may be supportive of long term immune health.
Another important part of a healthy immune system is a robust and diverse microbiome. To learn more, read: 12 Science-Backed Ways Probiotics Benefit The Immune System
When Should I Worry About My Child’s Frequent Illness?
Despite exposure to childhood illness being a way in which our immune systems mature and develop, there are situations where the frequency or severity of illness may warrant further investigation.
Too Much Sickness or Taking Too Long To Recover
If your child is experiencing more than the average number of illnesses, recurrent infections that are severe, or frequently not recovering from illness within the expected timeframe, it may indicate an underlying immune deficiency or other health issues. Don’t hesitate to reach out to your child’s doctor for testing and personalized advice.
Too Little Sickness
Supporting Your Child’s Immune System
The goal when it comes to supporting a child’s immune system is to fortify their immune system to allow it to perform at its best and to effectively deal with pathogens. A healthy immune system is able to mount effective and appropriate immune responses and recover from illness quickly and effectively. The best way to holistically support your child’s immune system is to focus on a healthy lifestyle, a nutrient dense diet, getting sufficient sleep, and to utilize supplementation as needed. Gut health also plays an important role in maintaining a strong immune system.
To learn more about supporting a healthy immune system, read: Important Immunity Terms To Know and Winter Immune Support For All Ages
Summary
It’s normal for children to experience frequent illnesses as their immune systems develop. Babies can get sick 6 to 12 times a year, preschoolers 7 to 10 times, school-aged children 6 to 8 times, and teenagers 4 to 6 times. Exposure to germs is how we “train” the immune systems to recognize and combat pathogens, building a robust memory of antibodies. While frequent sickness is typical, excessive or prolonged illness may indicate underlying health issues, and parents should consult a healthcare provider if concerned. To support a child’s immune health, focus on a balanced diet, adequate sleep, regular physical activity, stress management, and good hygiene practices.
References:
- University of Utah Health. (2021). Should I Be Worried If My Child Gets Sick Too Often? Healthcare.utah.edu. https://healthcare.utah.edu/the-scope/kids-zone/all/2021/12/should-i-be-worried-if-my-child-gets-sick-too-often
- Moraes-Pinto, M. I., Suano-Souza, F., & Aranda, C. S. (2021). Immune system: development and acquisition of immunological competence. Jornal de pediatria, 97 Suppl 1(Suppl 1), S59–S66. https://doi.org/10.1016/j.jped.2020.10.006
- Office of the Surgeon General (US); Centers for Disease Control and Prevention (US); Office on Women’s Health (US). (2011). The Surgeon General’s Call to Action to Support Breastfeeding. Rockville (MD). The Importance of Breastfeeding. https://www.ncbi.nlm.nih.gov/books/NBK52687/
- Coelho, G. D. P., Ayres, L. F. A., Barreto, D. S., Henriques, B. D., Prado, M. R. M. C., & Passos, C. M. D. (2021). Acquisition of microbiota according to the type of birth: an integrative review. Revista latino-americana de enfermagem, 29, e3446. https://doi.org/10.1590/1518.8345.4466.3446
- Collins, A., Weitkamp, J. H., & Wynn, J. L. (2018). Why are preterm newborns at increased risk of infection?. Archives of disease in childhood. Fetal and neonatal edition, 103(4), F391–F394. https://doi.org/10.1136/archdischild-2017-313595
- InformedHealth.org [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-. In brief: The innate and adaptive immune systems. [Updated 2023 Aug 14]. https://www.ncbi.nlm.nih.gov/books/NBK279396/
- Semmes, E. C., Chen, J. L., Goswami, R., Burt, T. D., Permar, S. R., & Fouda, G. G. (2021). Understanding Early-Life Adaptive Immunity to Guide Interventions for Pediatric Health. Frontiers in immunology, 11, 595297. https://doi.org/10.3389/fimmu.2020.595297
- Simon, A. K., Hollander, G. A., & McMichael, A. (2015). Evolution of the immune system in humans from infancy to old age. Proceedings. Biological sciences, 282(1821), 20143085. https://doi.org/10.1098/rspb.2014.3085
- Okada, H., Kuhn, C., Feillet, H., & Bach, J. F. (2010). The ‘hygiene hypothesis’ for autoimmune and allergic diseases: an update. Clinical and experimental immunology, 160(1), 1–9. https://doi.org/10.1111/j.1365-2249.2010.04139.x
- Ma, X., Buffler, P. A., Selvin, S., Matthay, K. K., Wiencke, J. K., Wiemels, J. L., & Reynolds, P. (2002). Daycare attendance and risk of childhood acute lymphoblastic leukaemia. British journal of cancer, 86(9), 1419–1424. https://doi.org/10.1038/sj.bjc.6600274
- Zhang S, Henderson TS, Scalchunes C, Sullivan KE, Jongco Iii AM. Persons Living With Primary Immunodeficiency Act as Citizen Scientists and Launch Prospective Cohort Body Temperature Study. J Particip Med. 2020 Nov 30;12(4):e22297. doi: 10.2196/22297. PMID: 33252341; PMCID: PMC7735893.
