Treatment training manual

4.12 How side effects are graded

Each side effect is reported slightly differently. But all side effects are graded from 1 to 4. Grade 1 is very mild. Grade 4 is very serious – life threatening or requiring hospital.

Side effect grades

GRADE 1 (mild)
Transient (goes away after a short time) or mild discomfort. No limitation in activity. No medical intervention required.
GRADE 2 (moderate)
Your daily activity is affected mild to moderately. You need some assistance. No or only minimal medical intervention is needed.
GRADE 3 (severe)
Your daily activity is markedly reduced. Some assistance is usually needed. Medical intervention is needed. Hospitalisation or hospice care possible.
GRADE 4 (potentially life threatening)
Extreme limitation to daily activity. Significant assistance required. Significant medical intervention, hospital or hospice care very likely.

Table: side effects graded

Side effect Grade 1 Grade 2 Grade 3 Grade 4
Diarrhoea 3-4 loose stools a day or mild diarrhoea lasting less than one week 5-7 loose stool a day or diarrhoea lasting more than one week Bloody diarrhoea or over 7 loose stools a day or needing IV treatment or feeling dizzy when standing Hospitalisation required (possible also for grade 3)
Fatigue Normal activity reduced by less than 25% Normal activity reduced by reduced by 25-50% Normal activity reduced by over 50%. Cannot work Unable to care for yourself
Liver toxicity AST or ALT levels 1.25-2.5 Upper Limit Normal (ULN) AST or ALT 2.5+ to 5.0 ULN AST or ALT 5.0+ to 7.5 ULN AST or ALT 7.5+ ULN
Mood disturbance Mild anxiety, able to continue daily tasks Moderate anxiety/disturbance, interfering with ability to work, etc Severe mood changes requiring medical treatment. Unable to work Acute psychosis, suicidal thoughts
Nausea Mild or transient reasonable food intake Moderate discomfort or intake decreased for less than 3 days Severe discomfort or intake decreased for minimal food intake for more than 3
Hospitalisation required
Rash Redness or itchy skin on part or whole body Rash that breaks skin, hard or soft pimples or light peeling/scaling Blistering, open ulcers, wet peeling, serious rash over large areas Severe rash, Stevens Johnson syndrome. Severe broken skin, etc
Vomiting 2-3 episodes a day or mild vomiting for less than one week 4-5 episodes a day or mild vomiting for more than one week Severe vomiting of all food and fluids over 24 hours or needing IV treatment or feeling dizzy when standing Hospitalisation for IV treatment (possibly also for grade 3)


Most information about the risk of side effects comes from the original studies when the drugs were first being developed. This is why it is very important to report to your doctor all side effects if you take part in any trials.

These studies collect information about frequency and severity of all side effects. However, studies for new HIV drugs generally only use small groups of people for relatively short periods of time.

Some side effects only become apparent after the drugs have been approved. This is becasue it might need thousands more people over a longer period of time.

Find out the risk of side effects are for any particular drug. What percentage of people get the side effects? This can help make informed decisions about which drugs to choose. Knowing what percentage of people needed to change therapy because of a side effect is useful too.

Accurate information on how many people get side effects may be provided by your doctor, or from a community treatment organisation. It is also usually included in the information that you get with all HIV drugs.

Side effects record sheet

Last updated: 1 January 2023.