Diagnosis, testing and treatment of COVID-19

The disease caused by coronavirus (COVID-19) is often mild but can be serious. Severe illness is more likely in older people and those with dementia. Our information here summarises symptoms of COVID-19, tests and diagnosis. It also covers support for a person with COVID-19. Even as the number of cases falls, we all need to remain vigilant.

What are the symptoms of COVID-19?

For 80 people in every 100 who have not been vaccinated, infection with coronavirus causes either no symptoms or symptoms mild enough to manage at home.

For 20 people in 100, the infection causes severe COVID-19, which needs hospital care. Older people and those with dementia are at higher risk of severe illness.

Vaccination greatly reduces the number of people infected with coronavirus who will need hospital care, including intensive care – at all ages. Vaccines have weakened the link between cases of the virus and hospital admissions or deaths.

Mild COVID-19

A person with mild COVID-19 will most often have one or more of:

  • high temperature (fever)
  • new continuous cough
  • loss of, or change in, sense of smell or taste. 

Some people also go on to get shortness of breath. Even ‘mild’ COVID-19 like this can still make it hard to get on with everyday life.

Severe COVID-19

A younger adult with severe COVID-19 will most often have serious problems breathing. In the most severe COVID-19 a person may also have disease of the blood (for example, sepsis), kidney, liver, heart and brain (for example, delirium). In these cases they may have cold, blotchy or sweaty skin, stop peeing, or get agitated, confused or very drowsy.

If a person has any symptoms of severe COVID-19 they need urgent medical care, so someone must call 999 and ask for an ambulance.

Atypical COVID-19

A person aged over 65 may have the common symptoms listed above. But they are more likely to have different (‘atypical’) early symptoms instead including: 

  • delirium - particularly in people with dementia
  • loss of appetite
  • diarrhoea or vomiting
  • weakness and fatigue
  • muscle or joint pain 
  • dizziness or falls.


Atypical symptoms are more likely as the person gets get older or frailer. They are also more likely in a person with other conditions such as dementia, heart disease and diabetes. Atypical COVID-19 is particularly common in people who live in care homes.

In older people, COVID-19 may start with what seem to be only mild symptoms (for example, diarrhoea and loss of appetite) but get worse quickly. This is one reason why regular testing for the virus in care homes is so important.

Diagnosis and treatment for coronavirus

Mild illness

Someone with symptoms of mild COVID-19 (as shown above) should rest and drink lots of water. Paracetamol may help with the fever and honey may help with the cough. The NHS has tips for home treatment, including what to do for breathlessness. 

Anyone who feels very breathless or week – or who can’t look after themselves –should call NHS 111 or their GP. The same applies for anyone who still feels unwell after four weeks. This could be ‘long COVID’.

A person being treated for mild COVID-19 at home must self-isolate and ask for a free PCR home test for coronavirus. NHS volunteer responders can help people who are self-isolating with food shopping, medication and other essentials. 

If at any time the person shows any symptoms of severe COVID-19 they need to go to hospital immediately (call 999).

Tests for coronavirus

The best test for coronavirus in a person with symptoms is the PCR (polymerase chain reaction) test . A sample is sent off to a lab and the result usually comes back the next day. This type of test is very good at picking up even very low levels of the virus.

For people without symptoms, a lateral flow test is better. The device is a bit like one for a pregnancy test. The result can be seen within 30 minutes. This is the kind of test people who are visiting a care home get. But anyone can order one for home delivery or collect them from a pharmacy. Lateral flow tests are good at picking up people with higher levels of virus, who are likely to be infectious.

Both tests use a swab taken from the nose and back of the throat. Instructions come with the kit and you can follow these tips on how to take a swab when the person has dementia

NHS advice on testing for coronavirus

Visit the NHS website for advice on when you can get a test.

Latest NHS advice

Severe illness

A person with dementia may develop severe COVID-19, perhaps with delirium, quite quickly. If so, they will need to go into hospital as an emergency. It is helpful if the person’s preferences about treatment are discussed beforehand when there is time and while they can. For example, the person may or may not want to be put on a ventilator to breathe for them or – if their heart or breathing suddenly stops – to have cardiopulmonary resuscitation (CPR).

No one has the right to demand medical care – including CPR and mechanical ventilation. If a doctor judges that the person’s chances of recovery with a good outcome are very low then they may decide not to follow such treatment.

There are different ways that someone can make plans in advance about their care while they still have the ability (mental capacity) to do so:

  • An advance decision to refuse treatment (sometimes called a ‘living will’) – if the person does not want a particular treatment. Doctors must follow this.
  • An advance statement – if they have future wishes about their care. Doctors must take this into account when they make decisions.
  • A Lasting power of attorney (LPA) for health and welfare – where the person gives their attorney(s) the power to refuse life-sustaining treatments (such as CPR and mechanical ventilation) if they became unable to decide for themselves. 

If a person is going into hospital (or a care home for the first time), it’s a good idea to put copies of the above documents in their bag. A completed copy of our patient profile document This is me can be really helpful too. This is me is a simple form to help nursing and care staff to understand and provide care for the person. 

The clinical team in hospital will make a diagnosis of severe COVID-19 from the person’s symptoms (as shown above) and various tests. The tests include their vital signs (temperature, blood pressure, heart rate, breathing rate), oxygen levels in the blood and a chest x-ray. Diagnosis also needs a PCR test for coronavirus infection. 

New treatments and vaccination have significantly improved survival rates compared with early on in the pandemic, but COVID-19 is still a potentially very serious disease. Medical treatment relies mainly on easing symptoms and supporting the person’s body while their immune system fights the virus. 

Unless they are very seriously ill, the person will generally be admitted first to a COVID-19 ward. If they get worse, they will usually be moved into a critical care unit.

Medical staff, family and the person themselves, as far as possible, will all be involved in deciding on treatments. Some of the more intensive treatments won’t be appropriate for some people, for a range of reasons. 

Depending on the person’s condition, hospital treatment may include:

  • paracetamol – for fever
  • medical oxygen or ventilation – with the drugs remdesivir and dexamethasone
  • management of delirium
  • antibiotics – in case the person also develops a bacterial infection
  • anticoagulant drugs – to prevent blood clots
  • fluids pumped into a vein – to keep them hydrated
  • sedatives – to relieve distress caused by breathlessness
  • other drugs – to maintain blood pressure, for example
  • management of other long-term conditions – for example, diabetes
  • nursing care – for example, regular turning to prevent pressure ulcers or maintaining nutrition by inserting a thin tube from nose to stomach.

Hospital doctors will make decisions about the person’s care by weighing up the risks, benefits and likely outcomes of each treatment option and considering the person’s preferences. This is why it’s helpful to have discussions beforehand.

The medical team will follow a ‘treatment escalation plan’ once the person is admitted. This sets out what will happen if the person’s condition worsens. For example, it will state whether they will be admitted to critical care or have cardiopulmonary resuscitation (CPR) – although that may also be recorded on a separate form.

The treatment plan also records whether the person has the ability to make decisions (mental capacity) about their care. Dementia by itself does not mean that the person lacks capacity but, as a person’s dementia progresses, they will lose capacity to understand the information they need to decide. 

If the person does get very seriously ill and the decision is for them not to have critical care, they will be given end-of life care on a ward. Family should be allowed to visit in these circumstances.

Read our general advice about hospital care

Leaving hospital

Because of coronavirus, there is new NHS guidance (in England and Wales) on how and when a person leaves hospital (discharge), whether they have coronavirus or not. 

Everyone being discharged from hospital to a care home will have a PCR test in the 48 hours before discharge. Patients who test negative will need to isolate in their room at the care home for 14 days.

Patients who test positive and are care home residents will first be discharged to a ‘designated setting’ to complete a 14-day isolation period. A designated setting might be a different care home or an NHS premises. It will meet strict infection prevention control standards.

A person with dementia may have complex care needs. The person should be assigned a case manager to manage their discharge and follow-up care, unless hospital staff judge that they can go home without support. 

For some people their care needs will be too high for them to go home – even with extra support – and they can’t stay in hospital. In this case they may be discharged to a care home or a rehabilitation bed, often in a community hospital – see our advice on recovery and rehabilitation after coronavirus (COVID-19).

Further advice

If you ever need any advice for symptoms, visit NHS 111 online or call 111 (or the GP) unless they seem urgent. In that case, call 999.

NHS 111 online
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