Lack of water for a tropical plant
Drying up is less terrible enemy, than overwatering, but long drying up can also be destructive for a plant. It is not always fatal (if, certainly, you have not already a crisp herbarium).
Symptoms of overbaking: unfortunately, signs of drying and overwatering are similar. However if the soil is dried up, fading of a plant will be faster: leaves fall, lose elasticity, and get thin as a paper.
Help: when the soil in a pot has completely dried up (in particular if the mix is peat-based), watering, even plentiful, can be ineffective. Put a pot in a basin with water on half an hour, then let superfluous water to flow down.
It is also useful to place a crone of a plant under a polyethylene package, preliminary having sprayed it.
Usually overdried plant comes to senses within several hours after an intensive watering. If it doesn’t happen, do not water any more: all the same sick roots of a plant cannot absorb water from the soil. Cover a crone with a package and, even if the dried up leaves will fall down, but the stalk has not dried up - there is a chance that there will be new leaves from buds.