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If you’ve ever wondered whether getting sick can delay your period or affect ovulation, you’re not alone.
Many people notice changes in their menstrual cycle after having a cold or the flu and question if the two are related. While these viral infections are usually short-lived, the physical stress they place on your body can sometimes lead to temporary changes in your cycle.
Here’s what the research says about how the common cold and influenza may affect your menstrual cycle.
Key Takeaways
- The flu and common cold can temporarily shift your period and menstrual cycle. This happens mostly through fever, stress hormones, and inflammation.
- Influenza triggers cytokines that raise cortisol and can delay ovulation. The result may be a period that comes later than expected.
- These menstrual cycle changes are temporary and usually return to normal.
- A common cold near the time of embryo transfer during IVF may affect implantation. But the evidence on this is limited.
- In men, influenza can temporarily reduce sperm quality. It can also lower motility and DNA fragmentation.
- Sperm abnormalities from the flu usually show up 4-11 weeks after the fever. They usually resolve over time.
- The common cold has little direct effect on male reproductive hormones or fertility.
What is the difference between a cold and influenza?
Colds and flu (influenza) are among the most common viral infections worldwide and are both contagious respiratory illnesses. But they’re caused by different viruses and they affect the body differently.
Flu symptoms come on fast and hit hard. They include:
- Fever
- Body aches
- Fatigue
- Sore throat
- Chills
Cold symptoms are usually more mild:
- Runny nose
- Mild sore throat
- Low-grade fever, if any
The flu is much more likely to cause the kind of systemic inflammation and fever that can affect your period, hormones, and fertility.
How does the flu affect fertility?
First, let’s get into how the flu affects female and male fertility.
How does the flu affect the female menstrual cycle?
Influenza makes you feel terrible. But it also triggers a stress response throughout the body that has the power to temporarily shift your menstrual cycle.
Here’s what happens.
When the influenza virus enters the body, the domino effect begins. First, the immune system releases inflammatory molecules called cytokines to fight the infection. Then, these cytokines activate the body’s stress response, which, in turn, boosts cortisol production.
Higher cortisol and systemic inflammation can temporarily mess with the release of reproductive hormones. That includes the ones that are in charge of follicle development, egg maturation, and ovulation.
The result?
- Ovulation might be delayed.
- Your period might start later than expected.
- Your period cycle length might increase (temporarily).
Studies show that these changes are small, dependent on your phase, and are fully reversible in the next cycle. There is no evidence that you will experience any lasting reproductive harm from uncomplicated flu.
Females also generally have stronger immune responses than males. This means the flu can affect women differently. Also, immune activity can vary across different stages of life and the menstrual cycle.
How does flu affect male fertility?
Men aren’t immune to the reproductive effects of influenza either. And you may be surprised to learn that the impact isn’t small.
Sperm quality and DNA
Influenza (especially H1N1) can temporarily lower sperm quality due to fever and systemic inflammation.
Changes include:
- Lower sperm concentration
- Lower sperm motility
- Abnormal sperm morphology
- Higher sperm DNA fragmentation
- Damage to sperm’s genetic material
- Lower overall semen quality
These abnormalities usually show up 4-11 weeks after fever. This reflects the full duration of sperm development (spermatogenesis). Recovery usually happens over the following months.
Researchers believe these effects are likely caused by:
- Systemic fever raising the body’s temperature around the testes.
- Oxidative damage.
- DNA damage that causes developing sperm cells to die off prematurely (apoptosis).
Animal studies show that influenza might cause chromosomal abnormalities in sperm. This can impact fertility. A few studies suggest that influenza might have delayed effects on sperm that could affect fertility for several months after illness.
There’s currently no evidence that influenza causes permanent infertility. But if you’ve had the flu with a high fever and are trying to conceive, it’s worth waiting 2-3 months before a semen analysis.
Know more: Sperm Motility and Fertility: Boost Your Baby Chances
How does the cold affect fertility?
Next, let’s get into how the common cold can alter fertility in women and men.
How does a common cold affect female fertility?
For most women, a common cold has little effect on the menstrual cycle.
Cold viruses (rhinoviruses) stay in the upper respiratory tract and usually don’t produce the high fever or widespread inflammation that the flu does.
But one small study found different results for women undergoing IVF and embryo transfers. It showed that women who got a common cold within 10 days before or after their embryo transfer weren’t able to get pregnant. This is even though they showed normal embryo development and uterine lining thickness.
This suggests that respiratory infection around the time of transfer might block embryo implantation. The cause is systemic inflammation or illness-related pressure.
Note that this study was small and hasn’t widely been replicated.
If you’re undergoing fertility treatment like IVF, talk to your healthcare provider if you start showing cold or flu symptoms around a planned transfer.
How does a common cold affect male fertility?
There is barely any evidence that the common cold directly affects male reproductive hormones or fertility. That’s because the common cold usually doesn’t extend beyond the upper airways and rarely triggers the body-wide inflammation that disrupts sperm production.
Temporary hormone changes might happen if a cold comes with fever or severe inflammation. But these are probably due to the body’s general illness response, not from the rhinovirus itself.
How can you manage flu and common cold symptoms?
Dealing with the flu during your cycle or the effects of illness on your fertility? Here are things you can do to support your body.
- Treat fever and pain as advised by your healthcare provider. If needed, use fever-or pain-relieving medication according to your doctor’s recommendation. If you’re TTC, talk to your doctor before using NSAIDs (like ibuprofen) around ovulation.
- Using gentle heat from a heating pad or warm water bottle may ease menstrual cramps and body aches.
- Drink plenty of water and warm fluids.
- Rest and get enough sleep. This supports immune recovery and hormonal balance.
- Eat a balanced diet with vegetables, fruits, protein, and whole grains to support immune function and hormone production.
- Avoid smoking and alcohol. They both increase oxidative stress and can make reproductive effects worse.
If you’ve recently had the flu with a high fever, your cycles may look off, and ovulation might vary. And that’s where the Inito Fertility Monitor can help. It tracks key fertility hormones–including estrogen, LH, FSH, and PdG (a urine metabolite of progesterone) – to identify your fertile window and confirm ovulation, making it easier for you to understand your cycle (even when it doesn’t follow its usual pattern).
When should you see a doctor?
Contact a healthcare provider if you experience:
- High or persistent fever with severe symptoms that don’t improve after a few days.
- Flu symptoms that seriously worsen after initial improvement.
- Severe menstrual pain, heavy periods, or unusual changes to your cycle after illness.
- Your period doesn’t return, or your cycles are still abnormal for several months after recovery (once you are sure to rule out pregnancy).
- You are undergoing fertility treatment and develop cold or flu symptoms.
- Your partner had the flu with a high fever, and you’re worried about how it may have affected sperm quality.
Conclusion
How your flu and common cold can affect your cycles depends on several factors, including the severity of the infection, whether you have a fever, and where you’re at in your menstrual cycle.
For most people, the effects are temporary.
Flu may delay ovulation, shift cycle length, and temporarily reduce sperm quality in men. In comparison, the common cold is less likely to affect fertility. But if you’re going through IVF, getting sick around the time of embryo transfer might influence your treatment outcomes.
You can support faster recovery by managing your symptoms ASAP, reducing stress, and getting enough sleep. If your menstrual cycle doesn’t return to normal or you have concerns about your fertility, or you become sick during fertility treatment, its best to speak with your healthcare provider.
FAQs
Yes, the flu can delay ovulation and push your period later than expected.
This happens because fever and inflammation raise cortisol levels. This, in turn, messes with the hormones that control your menstrual cycle.
A common cold probably won’t shift your period the way the flu can. Rhinoviruses usually don’t interfere with the hormones that regulate your cycle.
The only exception is if the cold comes with a severe fever or inflammation.
Occasional colds and flu shouldn’t cause long-term cycle disruption. The effects are usually temporary and resolve once you’ve recovered from the illness.
But if you’re getting sick frequently and your periods are consistently irregular, you may want to reach out to a physician to rule out other underlying causes.
Yes, some viral infections can temporarily cause irregular periods. They do this by disrupting reproductive hormone signals through fever, inflammation, and cortisol.
Thankfully, these changes are usually short-lived.
If your menstrual cycles stay irregular after you’ve recovered, or you miss several periods, see your doctor.
Yes. Being sick (especially with the flu) can delay your period by disrupting ovulation.
If ovulation happens later than usual, your period will happen later, too.
This is one of the most common causes for a temporary late period that isn’t related to pregnancy.
Most common viral infections, like colds and flu, only cause temporary effects on fertility.
Some specific viral infections (like mumps after puberty) can cause inflammation of the testes and might impair sperm production. Chronic infections (like HIV, hepatitis B, or C) might also affect reproductive health.
If you’re worried about a viral infection and your fertility, talk to a healthcare provider.
In most cases, no. Being sick with a cold or flu does not cause infertility. The effects on your cycle and sperm quality are usually temporary and reversible.
However, severe or untreated infections (especially those with high fever and severe inflammation) can have a more pronounced temporary impact on fertility.
Untreated sexually transmitted infections like chlamydia and gonorrhea may lead to pelvic inflammatory disease (PID) in women or scarring of the reproductive tract. This can increase the risk of infertility.
Some viral infections, like mumps, can affect the testes and lower sperm production.
Common respiratory infections like colds and flu usually don’t stop fertility. But they can temporarily reduce sperm quality or shift your cycle.
In men, infections that cause high fever (like influenza) can temporarily reduce:
- Sperm quality
- Sperm motility
- DNA integrity
Certain viral infections have been linked to impaired male fertility (especially mumps after puberty). HIV and chronic hepatitis infections might also affect reproductive health.
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