Chlorosis.
Yellowing of normally green leaf tissue caused by reduced chlorophyll production or chlorophyll breakdown.
What it means for your plants
The pattern points to the cause: yellowing of older leaves suggests a mobile nutrient such as nitrogen or magnesium, yellowing between veins of new leaves suggests iron or manganese often linked to high pH, and general yellowing with wet mix points to root damage. Check roots and watering before adding fertilizer.
A pothos with yellow lower leaves in a constantly wet pot needs a root check, not more plant food.
Put it into practice
Which leaves yellow, and how, points to the cause: old-leaf turnover, wet roots, low light, cold, pests or nutrients. A pattern-by-pattern diagnostic guide.
Yellow leaves on houseplants: read the pattern to find the cause