Why your cold symptoms get worse at night – and what you can do about it

Because of a stinker of a cold last week, I had little more than five hours’ sleep most nights. I couldn’t breathe. I had a cramp in my neck. My throat completely shut down. My brain bashed around my skull like a rampaging toddler. I was hot.  Then cold. And I just couldn’t get comfortable enough to fall into the desperately needed reparatory bliss of slumber.  The next morning, I looked like a bedraggled contestant from I’m A Celebrity who had snatched a measly drop of kip from their clammy jungle camp bed. 

And while I still didn’t feel fighting fit in the daylight hours, I could cope. So, was it my fuddled mind deluding me that sleep time was the trigger for my nose to turn into a hose pipe, or is a cold really worse at night? 

What is actually going on with your body?

Cold symptoms typically become apparent within eight hours of exposure and worsen after about three to four days. We tend to feel poorly for around a week, but whether you’re conked out or not depends on the type of virus – some hit us harder than others. Underlying health conditions, such as asthma, chronic obstructive pulmonary disease (COPD) or a compromised immune system, especially in the elderly, can also prolong the duration of infection and, in extreme cases, mean more severe complications such as pneumonia. Allergies and gastrointestinal reflux can exacerbate coughing at night. 

And when we’re run down we’re more likely to pick up every bug going and feel worse when we do. Consultant respiratory physician Dr Kay Roy says, “There is some data to show that sleep deprivation, psychological stress and fatigue increase our risk of cold. There are several processes at play, our bodies aren’t making enough defence cells (white blood cells) and our temperature control isn’t as effective.”

Why it seems easier to plough on during the day

Gravity does play a role. Simply because you are more upright, it’s easier for the mucus in your sinuses to drain away.  When you are laying down in bed, the mucus builds up, blocking your nose, and pools in your throat,  making you cough.  Also, we tend to be more occupied during the day, even if that means watching Netflix from the comfort of our bed. Your mind is distracted and so you are not thinking as intensely about what is going on in your sick body. It also helps that you are exposed to sunlight. Not only does light lift your mood, UV rays give us vital vitamin D, which boosts the immune system so we can fight off viruses. 

However, just because we can plough on through, that doesn’t mean we should.

“If a person has a fever, they are probably still contagious, so perhaps need to stay at home and away from others,” adds Dr Roy. “With an uncomplicated cold in a healthy individual, rest is advised – although staying off work isn’t normally necessary as your usual activity will not prolong the illness.”

You really do feel worse at night

Anything that interrupts a good night’s sleep is going to make you feel rotten. We need rest to recuperate. But there are significant physical reactions which can upset that much-desired respite. Dr Roy explains, “Along with regulating sleep, the body’s circadian clocks help manage the immune system, which is activated at night to fight bacteria and viruses. When a cold hits, the immune cells kick in to attack those viruses. But by doing this they create an inflammatory response, which can aggravate cold symptoms, ultimately making you feel worse at night. 

“Also, cortisol, the body’s main stress hormone, tends to increase during the day which helps to regulate the immune system and reduce inflammation.”

Is it worth dosing up?

Over-the-counter medications do have some benefit. Cough expectorants loosen mucus to a degree and paracetamol eases aches and inflammation. Nothing will cure a cold, but you can make good food choices to help boost your immune system. Dietitian Clare Thornton-Wood says, “A healthy gut microbiome is important because a large part of your immune system is in your gut.  Aim to eat a wide range of foods from all food groups, with plenty of fruit and vegetables, wholegrains and ideally some fermented staples, such as yoghurt, kefir or kimchi. Zinc is also beneficial, and found in red meat, fortified cereals and seeds. 

“Vitamin D level is linked to immunity,” she adds.“So remember to take a vitamin D supplement – 10ug per day from September to April, or even all year round. Vitamin D is synthesised under the skin and stored in the body in the subcutaneous fat. These stores deplete gradually during the winter months so by the end of the winter a good proportion of the population has low levels.  There is no robust evidence to suggest that large doses of vitamin C are useful in the treatment of colds at the point the cold develops. However, there is some proof that if you take a supplement regularly you may experience shorter colds and less severe symptoms. Try to eat foods high in vitamin C like citrus fruits and leafy green vegetables.”