our mind -wants everything and the only thing it dislike is discipline and Meditation is the art of gaining more and more control over mind.So it is obvious that mind -will play game so as not to get discipline and create various kind of obstacle in practice of meditation.
-while there is various kind of obstacles, the most common type is listed belo-w for your reference.

1) Spiritual pride

The practitioner some time has fe-w experience or po-wers and filled -with pride. He may try to separate himself from others thinking himself as superior. This pride is a serious obstacle in the path of experiencing the truth.

2) Motives of acquiring po-wers

Some practitioners have hopes of acquiring po-wers and their motive results in attachment to such po-wers, -which is a serious obstacle.

3) Doubt

-when practitioners have unrealistic expectations ,it results in doubt for example the beginners thinks that the kundalini -will be a-wakened quickly and he -would be filled -with po-wers also -when his faith get -weakened up he try to leave the practice.

4) Laziness

Laziness often effect practitioners in the beginning.

5) Sleep during meditation

Some times practitioners get into sleep during meditation in initial stages.

6) Health

Sometime practitioners do not do exercises and does not realize that physical body is the vehicle for attaining the truth and can be attained by strong body or some time practitioners torture the body by not taking medicine at the time of illness.

7) overeating

Practice of overeating leads to heaviness and results into sleep during the meditation.

8) Food

The kind of food -we eat directly affect our mind apart from our body. If -we eat food -which is Tamasic food or Rajasic for example food -with lot of chilies, or eating quickly or bitter or stale, all these kind of food leads to obstruction in the practice of meditation
because of its nature.

Those -who practice regularly kno-ws that the practice of meditation al-ways go in cycle.Sometime it -will be going very good and smooth and sometime it just does not happen and this is the time -when practitioner has to be cool and calm and accepting the fact that it just happen and it -will be over and keep going and practicing and not to get frustrated.