Is it thirsty or drowning?
Few house-plants suffer from ill health except as a result of mistreatment. More plants die from the over-generosity of the owner than any otherand some succulents grow well together. Both these kinds of plants sometimes become infested with mealy bug, so inspect the plants regularly.
A plant which is drowning reveals its discomfort first by listless behaviour, a failure to grow or to shine. Then one or two of the lowerbegin to turn colour and after a while will drop. If the are examined they may even be turning mouldy.
Unfortunately many of the symptoms of a plant which is suffering acute thirst are the same as those for a plant which is drowning, the same yellowingand the same fall. So you will have to search your conscience to see whether you have in fact been giving your plant too much or too little water. In the latter case it can happen that a brief and accidental period of neglect is followed by more reasonable care. But during this period of neglect the ball has dried out to the extent that subsequent cannot be absorbed by the brick-hard soil or peat mixture. So although you appear to be watering correctly, in fact the plant is not able to absorb the water. It needs a good soaking in a bucket of water to get the soil into a state again where it can absorb moisture.
But although there is a fairly quick and easy way to cure a plant which is too dry at the roots, there can be no quick and easy correction of a state of drowning. Obviously watering will have to cease for a period, but apart from this little can be done except the kill-or-cure method of knocking the plant from its pot andin dry soil, after scraping away as much as possible of the old over-wet . This may succeed and it may not, depending mainly on the strength of the plant.