A new type of age ‘clock’ can assess chronic inflammation to predict whether someone is at risk of developing age-related disorders such as cardiovascular and neurodegenerative disease. The clock measures ‘biological age’, which takes health into consideration and can be higher or lower than a person’s chronological age. The inflammatory ageing clock (iAge), reported on 12 July in Nature Aging, is one of the first tools of its kind to use inflammation to assess health. Other age clocks have used epigenetic markers, chemical groups that tag a person’s DNA as they age and are passed along as cells divide. Keeping timeiAge is based on the idea that as a person ages, their body experiences chronic, systemic inflammation because their cells become damaged and emit inflammation-causing molecules.