Chlorosis is a disease symptom (deficiency symptom) in land plants, e.g. grapevines, caused by a lack of chlorophyll. The disease has a characteristic pattern of damage: usually, the leaves have a typical yellow coloring; leaves are often damaged and look burned, sometimes, even necrosis occurs (death of the leaf tissue).

Chlorosis is usually an indicator for a lack of minerals (in particular, boron, iron, magnesium, sulfur, or nitrogen deficiency) and often also suggests a too high salinity the soil. The disease can also be triggered by long-lasting water shortages as it causes nutrients to no longer be transported in sufficient quantities.