Recognising red flags

We are taught from the start of our nursing careers to look out for red flags: but what are they, and how do we recognise them? This guide aims to help us distinguish the significant from the unimportant

In medicine, a red flag is a sign or symptom that alerts us to the possible presence of a serious or life threatening condition. We need to check for red flags when a patient presents with a group of symptoms that could mean a sinister or life threatening condition, even if other conditions are (much) more likely.

Red flags need urgent or immediate further action. They are not diagnostic on their own, and may mean little if not supported by other findings in the history and examination, but they raise suspicions and help us stratify risk.

Red flags have medicolegal significance. Failing to ask about them can lead you to miss a serious diagnosis, and suggests that you did not consider it or attempt to rule it out.

This article offers an overview of red flag symptoms, and tries to cover the principles of what to ask and broad areas in which questions lie.

TOO MUCH TO KNOW?

There are thousands of serious conditions with associated red flag signs and symptoms. General practice nurses are increasingly at the forefront in primary care, but don’t have the length of diagnostic training given to GPs. They may worry that they have not been given the chance to know everything, and are therefore vulnerable. A common concern is that they could lack one tiny but crucial bit of obscure knowledge of a rare symptom, which could lead to a serious diagnostic error. This concern is particularly sharp when first involved in seeing patients with new presenting complaints, when dealing with patients on the telephone, and when under time pressure.

Of course no one can know everything. What protects us from missing serious conditions is being thorough and systematic, having as broad a knowledge as we can, being aware of the kinds of conditions which might underlie symptoms, and understanding the kinds of red flag symptoms that should alert us to the need to look further. And, of course, asking for help if we are uncertain.

THE DIAGNOSTIC SIEVE

When you see a patient you should ‘sieve’ their presentation through this question:

Is there a serious condition, however rare, which could produce these symptoms?

The question isn’t WHAT rare condition might produce these symptoms? It is COULD THERE BE one? You don’t have to know about all rare conditions. You need, instead, to know what types of serious conditions can cause particular presentations – e.g. cancer, sepsis, myocardial infarction – and what kinds of red flag symptoms they might also cause.

REMEMBERING TO ASK

The patient may tell you about red flag symptoms, but if they don’t you need to ask. It’s up to you when in the consultation you do this, as you need to balance letting the patient tell their story and using open questions to build a picture, against the more closed specific questions that look for red flag symptoms.

Box 1 gives an idea of how you can approach red flags in the history.

Types of red flags

Very broadly, red flag symptoms can be considered acute and chronic.

Acute red flags include

• Signs of collapse, circulatory compromise, disseminated intravascular coagulation (DIC)
• Signs of injury compromising function
• Altered consciousness/neurological deficit
• Prolonged distress, temperature or rash
• Psychosis, thought disorder, suicidal intention

Chronic red flags include

• Weight loss
• Pain and associated symptoms
• Blood
• Loss of function, particularly asymmetrical
• Difficulty breathing, difficulty maintaining circulation
• Progressive deterioration

DISEASE SYSTEMS AND ASSOCIATED RED FLAGS

No list can be completely comprehensive, but the next section offers a general overview of red flags by system and condition.

Cancer

Cancers can produce both local and general red flag symptoms. The general symptoms are more likely to come on later. Local symptoms can occur early.

Local effects include

• Pressure effects – e.g. pressure on nerves stops them working, producing unexplained altered sensation or loss of function.
• Pain. Cancer pain is typically unremitting and gets steadily worse, although this isn’t always the case. Brain tumour headaches are constant, absolutely never going away, worse in the mornings.
• Lump – particularly true of breast cancer, cancerous lumps are typically hard, non mobile and, at least early on, painless.
• Bleeding e.g. into the bowel (producing black or red stools), or into the airways (producing blood in the sputum), into the semen from prostate cancer, or from the nipple in some breast cancers
• Loss of function of the affected system e.g.
  • bruising when the blood fails to clot in acute leukaemia
  • altered eye movements in a brain tumour pressing on the optic nerve
  • weakness and lost sensation of the lower body in tumours pressing on the spinal cord
  • persistent limping in a child with a bone tumour
  • worsening jaundice due to metastasis in the liver upsetting liver function

These symptoms are unusual and distressing – you probably won’t need closed questions to discover them.

‘General’ red flags which are associated with many different cancers are sometimes more vague and chronic e.g.

• Unexplained weight loss
• Night sweats
• Unexplained anaemia
• Increasing breathlessness (due to anaemia or to primary or secondary lung cancer)
• Hypercalcaemia (leads to tiredness, constipation and confusion)
• Bone pain due to metastases – typically gradually increasing gnawing pain, worse on movement.

Respiratory conditions

• Unexplained weight loss
• Haemoptysis (blood in the sputum)
• Severe or increasing breathlessness

While these conditions can signify lung cancer they can also suggest other conditions such as tuberculosis, sarcoidosis, pulmonary hypertension and severe right heart failure. You don’t need detailed knowledge of these conditions to spot the red flags.

Breathlessness is generally a significant symptom. If an asthmatic or COPD patient has severe and increasing breathlessness they are likely to need admission. In anaphylaxis, difficulty breathing would be a red flag.

Cardiovascular conditions

In cardiovascular conditions, red flags are signs of heart pain or dysfunction, and of circulatory compromise. Red flags include:

• Crushing central chest pain
• Dizziness, breathlessness, sweating – suggesting a heart failing to keep up with demand
• Increasing pain in legs – brought on by walking, relieved by rest, suggesting claudication. If it turns into rest pain then there is likely to be critical ischaemia.

Bowel conditions

In any patient with bowel symptoms ask about:

• Bleeding – whether mixed in with stools, whether painful (haemorrhoids hurt when passing stools, cancer bleeding usually isn’t painful)
• Black stools (may be melaena)
• Altered bowel habit for 6 weeks or more, particularly in patients over 50 years
• Unexplained weight loss

Normal bowel sounds with passage of flatus and normal bowel habit suggest a bowel working normally. Look for:

• Rigid abdomen without bowel sounds – ileus, perforation
• Colicky pain with vomiting and obstructive bowel sounds – suggests obstruction
• Features of sepsis (see below)

Neurological conditions

Cancers and other causes of pressure on nerves can permanently impair their function, e.g. from a centrally prolapsed intervertebral disc. Cerebrovascular, septic, toxic or metabolic conditions may also affect brain function. Red flag symptoms include:

• Confusion/altered consciousness
• Loss of motor function or speech
• Loss of balance/altered gait
• Unilateral changes to an eye e.g. proptosis
• Progressive loss of neurological function
• Unremitting headache worse on waking
• Sciatica, particularly in both legs – check for bladder and bowel function

Ear, nose and throat (ENT)

Red flags for cancers in the ENT system include.

• Unilateral bloody nasal discharge
• Unilateral new onset deafness, can signify tumour on the hearing nerve
• Multiple ENT symptoms together e.g. hearing loss, deafness and dizziness
• Hoarseness of the voice for more than three weeks is carcinoma of the larynx until proved otherwise

Genito-urinary (GU)

Cancers may be associated with bleeding or swelling. Check for:

• Unexplained vaginal bleeding, especially after intercourse (cervix, uterus)
• Pain or blood on ejaculation (prostate)
• Unexplained abdominal swelling (ovary)
• Non-healing lesions on the genitalia – typically nodules or ulcers (cancer, syphilis)
• Pain in the prostate or blood in the ejaculate (prostate cancer).
• Suddenly worsening prostatism, or prostatism occurring at unusually young age.

Urinary obstruction

• More common in men. It is preceded by increasing difficulty in starting the stream. A palpable bladder in a patient with these symptoms is a red flag sign suggesting impending complete obstruction.

Eye conditions

• Absent red reflex in a baby (cataracts or ocular tumour)
• Flashers and floaters and halos – sudden increases can suggest retinal tears and detachments or glaucoma
• Curtain coming down on the vision – suggests retinal detachment
• Double vision – can (although usually does not) signify cerebral tumour

Skin

• Non-healing lesions anywhere
• Large or enlarging pigmented moles that change, crust or bleed (melanoma). If you are inexperienced at looking at moles, get a second pair of eyes to check.
• Rashes – purpuric rashes (DIC, sepsis), prolonged red rashes (Kawasaki disease), flitting red rash associated with possible exposure to tick bite (Lyme disease).

Pregnancy

• Loss of foetal movements
• Excessive or dramatic foetal movements
• Abdominal pain
• Swelling of hands, face and feet
• Increasing blood pressure
• Vaginal bleeding
• Severe, generalised itching

Metabolic conditions

Red flags may be

• Altered consciousness
• Collapse
• Ketotic breath with sighing breathing
• Hyperglycaemia with positive ketones
• Pallor and collapse in hypoglycaemia (consider in diabetic patients on treatment)

Psychiatric conditions

• Active suicidal intent
• Thought disorder – psychosis, hallucination, paranoia

Child development, child protection

• Worrying parental behaviour – Failure to present, aggression, non-matching stories
• Any bruises on a baby
• Broken bones under the age of 3 years
• Regression of developmental progress
• Sexualised behaviour

Sepsis and infection

Sepsis is a severe infection threatening circulatory compromise.

If the patient is collapsed or has altered consciousness this will be obvious if you are with them. When the consultation is on the telephone it’s important to ask how the illness has affected them. If they are old enough, ask to speak to them. If they can’t get to the phone ask why not. Ask what children are doing. A young child playing normally with their toys is unlikely to be confused or collapsed, whereas one lying on the sofa looking too weak to move might be.

Early red flags for sepsis include

• Rashes that do not blanch. Purpuric rashes in sepsis are due to bleeding into the skin due to a condition called diffuse intravascular coagulation (DIC). The clotting system is beginning to fail. Not all purpuric rashes are caused by DIC – but DIC needs to be ruled out as patients can be surprisingly well at the start.
• Severe vomiting (sepsis, UTI, gastroenteritis and some types of poisoning.)
• Confusion
• Hypotension
• Tachycardia
• Peripheral shut down – cold hands and feet
• Limb pain
• Mottled appearance

Temperatures

Prolonged temperatures become red flag symptoms. This generally means longer than 48 hours without explanation, although the longer it goes on the greater the concern.

• Temperatures above 39 degrees in an older child, above 38 degrees in a child under three months of age. High temperatures commonly signify self-limiting viral illnesses, but may signify focal infection or more serious infection.
• A prolonged fluctuating temperature in a child, with a flitting red rash may signify Kawasaki disease. Prolonged pyrexia can also mean an unexplained source of infection (e.g. UTI, abscess).
• Foreign travel. Any temperature in a patient recently returned from a malarial zone is malaria till proved otherwise. Anything up to 6 months can be a risk, although the risk is greatest in the first month.

Babies

Signs and symptoms in babies are often subtle.

Red flag conditions particular to babies include:

• Parental concern (common but should always be listened to)
• Concerns over parental bonding
• Maternal depression
• Not moving all four limbs equally (injury or brain condition)
• Floppy or rigid (sepsis, injury, congenital abnormality)
• Mottled, blue (circulatory collapse)
• Struggling to feed or cry (illness, weakness, bronchiolitis)
• Crying constantly (undiagnosed condition which may be serious)
• Bruising (suggests injury or bleeding problems)
• Shrunken fontanelle (dehydration)
• Bulging fontanelle (brain infection)
• High temperature (sepsis)
• Failure to thrive (multiple causes)
• Eye rolling, jerking movements, asymmetrical movements (brain injury, fits)
• Irritability (can signify infection, injury, fits, congenital abnormality)
• Jaundice (mild jaundice is common up to three weeks of age in breastfed babies, more severe, worsening or prolonged jaundice can signify serious liver disease)

Summary

Red flag symptoms and signs raise suspicions of the possible presence of serious disease. If the serious disease presents ‘full on’ we can use them to help confirm our thoughts and fears, and to support our urgent referral. This part is arguably easier.

The wider use for red flags, however, is when seeing common, non-serious or self-limiting conditions which just may, somewhere in a long list of differential diagnoses of varying likelihoods, include something serious. Red flag questions allow us to double check that we haven’t missed something which really matters, and to make doubly sure that our more innocent explanation of the patient’s presentation is supported by the evidence. They allow us to raise or lower our suspicions accordingly. The presence of red flags does not prove sinister disease, and their absence does not mean it isn’t there.

Knowledge and understanding of red flag symptoms is an important part of history taking, and it is important to record negative as well as positive findings, but it is only useful when combined with thorough history and examination, listening to the patient and adopting a systematic and thoughtful approach.