Unstable angina: symptoms, treatment and when to call 999

Angina is a pain or uncomfortable feeling when blood flow to the heart is reduced. The NHS says it happens when the heart does not get enough blood, usually because coronary heart disease has narrowed or blocked the blood vessels supplying the heart with fatty deposits. The British Heart Foundation (BHF) describes several types. Stable angina is the most common type, tends to happen when the heart works harder, such as walking uphill, and goes away with rest. Unstable angina is different: it can feel unlike your usual angina, can occur at rest, feels more severe and lasts longer.

The key point is the change in pattern. Chest pain that is new, more frequent, more severe, longer lasting or comes on with less effort than before should be treated seriously, because it can indicate a blood vessel that is narrowing further.

The British Heart Foundation separates angina into types. The pattern of symptoms is what tells stable and unstable angina apart.

The NHS says the main symptom of angina is sudden pain in the chest, neck, shoulders, jaw or arms, which may feel like tightness, squeezing or pressure, or a dull ache, and may make you feel sick, breathless, dizzy or sweaty. The BHF adds that angina feels different for everyone, and that it can also be felt in the back or stomach, with fatigue among other symptoms. It notes that women are more likely than men to have less common symptoms such as feeling sick, sweaty, dizzy and breathless.

• Chest pressure, tightness or squeezing, or a dull ache.

• Pain that spreads to the arms, neck, jaw, shoulders, back or stomach.

• Feeling sick, sweaty, dizzy, breathless or very tired.

• Symptoms at rest, or lasting longer or feeling stronger than your usual angina.

• Symptoms that do not improve with rest or your angina medicine.

The NHS says to call 999 if you have been diagnosed with angina and have chest pain that does not stop after resting for a few minutes or after taking your angina medicine, or if you get sudden pain or discomfort in the chest that does not go away, including pressure, burning or indigestion, pain spreading to the arm, neck, jaw, shoulder, stomach or back, or chest pain with sweating, sickness, light-headedness or breathlessness. It says you could be having a heart attack and need immediate treatment in hospital, and not to drive yourself to A&E.

The NHS says to get help from NHS 111 if you have chest pain or other symptoms of angina that come and go, or if you have been diagnosed with angina and it feels worse than before, is happening more often, lasts longer or happens when you are resting. If in any doubt, call 999.

The NHS heart attack page, which applies when someone may be having a heart attack, says to sit and rest on the floor in a comfortable position, with your knees bent and your back supported, or on a chair if you cannot do this. It says to take aspirin (300mg) if you have any and are not allergic, and to take your glyceryl trinitrate (GTN) spray if you have angina and have it with you.

It also says to keep checking someone who may be having a heart attack to make sure they are still responding and breathing, and to start CPR if they stop responding and stop breathing. Do not drive yourself to A&E.

The BHF says the most common cause of angina is coronary heart disease, in which arteries are narrowed by a fatty substance called plaque. Triggers include physical activity, emotional stress, cold weather and eating a meal, and a big meal can trigger symptoms. The NHS says you are more likely to get angina if you are a man aged 45 or over or a woman aged 55 or over, smoke, drink more than 14 units of alcohol a week, are living with obesity or overweight, have high blood pressure or high cholesterol, have had heart problems before, have close relatives with heart problems, or have another condition such as diabetes, arthritis or kidney disease.

The NHS says that if a GP thinks you may have angina you will be referred to a heart specialist (cardiologist). The NHS lists the tests you may have: blood tests, an electrocardiogram (ECG) to check the electrical activity of the heart, checking the level of oxygen in the blood, and scans such as an angiogram, MRI scan or CT scan. The BHF also lists an ECG, coronary angiogram and heart scan.

The NHS says treatment for angina may include medicine to treat an attack (glyceryl trinitrate), medicine to lower the chance of attacks such as beta blockers, and medicine to reduce the risk of stroke or heart attack, such as low-dose aspirin or statins. Sometimes surgery to increase blood flow to the heart, such as coronary angioplasty or a coronary artery bypass, is recommended. The BHF describes a coronary angioplasty as a procedure where a balloon is gently inflated to open a narrowed artery, often with a stent inserted to keep the artery open, and heart bypass surgery as another option.

Your cardiology team decides which of these is suitable, depending on what is seen on an angiogram and your general health.

The NHS suggests avoiding triggers as much as possible, such as stress, cold temperatures and large meals, always having your angina medicine with you, quitting smoking, keeping to a healthy weight, eating a balanced diet, being as active as symptoms allow and cutting down on alcohol if you drink more than 14 units a week. It says that with treatment the symptoms should improve over time and may eventually stop, and that if symptoms are well controlled angina will not usually have a big impact on life, though it may affect work if a job is very physical or involves driving buses, coaches or lorries.

The BHF stresses that panic attacks and anxiety can cause chest pain which is not angina, but you should not assume that new chest pain is anxiety without medical assessment.

Suspected unstable angina is an emergency. The NHS and the British Heart Foundation both direct people to call 999 if symptoms do not settle with rest or medicine, rather than waiting for a routine appointment.

After the emergency, ongoing assessment is led by the NHS cardiology service following a GP or hospital referral. Some people choose private cardiology for follow-up tests or a second opinion, which does not replace calling 999 for a new or worsening attack.