Sweating normally occurs at night when the room, environment, or bedding may be making you hot. Night sweats occur when you sweat excessively at night despite the surrounding environment being cool. In this case, it's likely that you will need to change nightwear and sheets if they get soaked through. Persistent night sweats can be a sign of serious health conditions and should be checked by your doctor if they occur.

Maskne is a new phenomenon coined in the COVID-19 pandemic to describe the acne experienced around the nose, upper lip, and chin area in a response to regularly wearing a mask. Mask-provoked acne is new to the general public but has long been experienced by medical and construction workers. The causes of these pimples, or whiteheads, are two-fold. First, the physical barrier that masks provide causes pores to become blocked with the dead skin cells we shed all the time, so-called acne mechanica. A bacteria associated with acne, called P. acnes, causes inflammation in blocked pores and sebaceous (oil-forming) glands. In addition to the physical friction, masks provide a warm, moist environment for P. acnes to grow and multiply, thus further inflaming the spots and even causing deep spots called cysts. As mask-wearing has become an important component of avoiding the virus in the current pandemic and essential in certain aspects of life, including in shops, public transport, and some workplaces and schools, maskne is a fact of life many of us need to adjust to. Simple measures can reduce physical irritation. If you want to wear a single-use mask, choose one with a structure that lifts away from the mouth and nose and seals around the edges. These look a bit like beaks. Choosing silk over other materials for reusable masks may cause less friction and irritation and be more breathable while still offering protection. You should make sure you wash these regularly. Regular and gentle cleansing can help to reduce skin congestion and clogged pores. Wearing make-up that claims to be non-comedogenic (non-spot-forming) and looking for chemical exfoliants in creams and serums, such as salicylic acid, glycolic acid, and lactic acid, will all help to keep spots at bay. You can also buy targeted spot treatments from your pharmacist to help with individual blemishes.

COVID-19 is a virus that can affect all systems, and while most think first of it as threatening our breathing, it can also present a considerable burden to the skin. Doctors have seen increased numbers of skin rashes and irritations, and there’s anecdotal evidence that it can impair wound healing. For 1 in 5 with COVID-19, a skin sign is the only symptom they have. COVID-19 skin signs fall into two categories – common conditions that have become much more common, such as urticaria, and rare conditions that have increased, such as those affecting the toes or mouth. It’s not clear if the virus causes these changes directly or via the immune response it provokes, but nearly half appear at the time of infection – about a third appear after infection. It’s worth noting that it’s common to get a rash after any mild viral illness, such as a cold.

High temperature, fever, chills, or any other name you give it, is a sure sign that your body's immune system is at work trying to fight something off. The common causes of a high temperature are viruses or bacteria causing infection, but there are many other causes. You will normally feel unwell with a fever and may be swinging from feeling cold and shivery and getting under the covers to burning up and feeling hot and sweaty. You may have a hot head, chest, or back when you put a hand to it.

A cough is the body’s natural way of responding to irritation in your respiratory tract. When specialized sensors in your airways detect an irritant such as smoke, dust or pollution, it triggers a cough reflex that causes the muscles in your airways to contract and pushes a burst of air out through your airways in an attempt to remove the cause of the irritation – this is a cough. A dry cough is when you cough without bringing up any mucus or phlegm and can be irritating for your throat. It is a very common type of cough that can be caused by an infection, asthma, environmental irritant or irritation caused by acid reflux. It may also be a side effect of certain medications such as ACE inhibitors, used to treat high blood pressure. A constant dry cough is the result of your cough reflex becoming more sensitive than usual.

Phlegm, also known as mucus, is produced by your lungs to line the airways and protect them from foreign substances. It provides moisture which helps to trap irritants and remove them from the body. In certain situations, your body might increase the production of mucus, for example, when you have an allergy or an infection, which might cause unpleasant symptoms. When you cough up phlegm from the lungs or back of the throat, it's often referred to as sputum. Looking at your phlegm or sputum can give you a lot of information about what could be causing your symptoms.

Anosmia is a condition that describes failure of our sense of smell. Although there are many other conditions that can cause anosmia, it has become well-known since the pandemic started, as it was classified as one of three typical symptoms of COVID-19 before people were vaccinated. Loss of sense of smell occurs during the acute COVID illness but can last long after you have since recovered. Your ability to smell is closely linked to your taste buds so it can make your food taste bland or alter your smell so that things either don’t smell of anything or smell very different. You may detect a charred or burning smell which can have an effect on your appetite. You may only be able to smell or taste a little – partial anosmia – or you may find certain smells or tastes unpleasant. You may experience a bad smell all the time, like smelling smoke or gasoline, even if it’s not present.

A blocked nose is the feeling that the nasal passages are congested or stuffy. Depending on the individual, a blocked nose can affect each person quite differently. A blocked nose can occur over a short period (acute) or a long period (chronic) of time, which is usually regarded as more than three months. A blocked nose can occur with other symptoms which may give an indication of the cause; for example, nasal discharge (rhinorrhea), loss of sense of smell or taste (anosmia), sneezing and irritation, pain in the face, or nasal bleeding.

This is characteristic of a fungal nail infection. Yellowing and thickening usually start at the tip, becoming soft and crumbly and harder to cut. Over weeks it can spread to the rest of the nail, replacing the healthy pink parts and causing it to lift off. Eventually, over the course of a few months, the whole infected nail may come off. People are usually bothered by the appearance, and only notice when summer announces itself and the flip flops come out, after a winter of feet in warm sweaty socks and shoes. It can occasionally cause swelling and pain. Tinea unguium, the medical term for fungal nail infection, is more common in the toenails than fingernails. It can affect one nail or several, usually on the same hand or foot, and can eventually spread to the other foot.

A cough is the body's natural way of responding to irritation in your respiratory tract, causing muscles in the airways to contract and push out any irritant or infection in a burst of air. Your airways are covered in cells that produce mucus which aids in the removal of dust, bacteria, viruses, and other debris. When you get a chest infection, your body produces more mucus than normal as it tries to remove the virus or bacteria. The excess mucus, known as phlegm or sputum, causes you to cough more frequently and forcefully – phlegm is then brought up and spat out or swallowed, destroying the pathogen and helping you recover. We call this a productive cough. Most chest infections and productive coughs are caused by viruses rather than bacteria. As antibiotics only work on bacterial infections, this means that they won't have any effect on most chest infections.

Blood in the sputum is also known as hemoptysis. Sputum is usually the mucus substance you cough up from the airways and lungs. Phlegm is the specific term for the mixture of saliva and mucus from your nose, mouth, and throat. There can be different causes for hemoptysis; some are serious, and some are less so, but you should see your doctor in most circumstances, so they can work out the underlying cause. You may notice a few streaks of blood in the sputum, which commonly come with a chest infection, or clots, or even a pink watery appearance. Still, these indicate an area of tissue damage and warrant a discussion with your doctor.