Here are some excerpts from a article by Ven.
Fazhao published in Vaidurya vol.27 touching on Karma, hopes
it can helps to clear some doubts.
' 'Karma' is not necessarily something that happens in the
future. A person with heavy karmic obscurations would have fear in
his heart. A person filled with fear would naturally not be healthy
physically. He may even have hallucinations resulting in
terror. '
'Karma arises from the mind. When karmic obscurations
manifest, an illusion is produced which leads us to experience the
fruition of karma. From past causes to present results; presents
causes to future results, Buddhism studies the present thought and
the development of future cause and effect. Not only does it study
the future, but the way to transform past negative karma. People
who know the law of cause and effect and put effort into making
positive changes will be healthy both physically and
emotionally.'
'From the Buddhist viewpoint, fame and gain, status and
glory are the positive results of past virtuous activities. If one
has not practised generosity in the past, even if one accquires
wealth in this lifetime, it will not stay. Causes, conditions,
fruition and results are not fatalistic but a message for all to
put effort into practising virtue, wisdom and compassion.'