I am experiencing high CPU usage here is the stats i got from server, the consumption after every restart in 15 minutes go upto 100%, what could go wrong?

I have a wordpress copy installed on the server which does not have much traffic, here is the stats that i got from using top command in server.

top - 11:46:02 up 12 min,  3 users,  load average: 40.89, 16.03, 6.11
Tasks: 132 total,  41 running,  91 sleeping,   0 stopped,   0 zombie
Cpu(s): 24.3%us, 61.5%sy,  0.0%ni,  0.0%id,  4.0%wa,  0.0%hi,  0.0%si, 10.2%st
Mem:   2050896k total,  1988656k used,    62240k free,      284k buffers
Swap:        0k total,        0k used,        0k free,     4712k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
   31 root      20   0     0    0    0 R   39  0.0   1:35.53 kswapd0
  899 root      20   0 15988  172    0 S   14  0.0   0:05.00 irqbalance
  418 syslog    20   0  243m  600    0 S   13  0.0   0:06.85 rsyslogd
  944 mysql     20   0 1320m  53m    0 S   12  2.7   0:21.15 mysqld
 2357 root      20   0 17344  532  164 R   11  0.0   0:14.27 top
  960 root      20   0  246m 3816    0 S    3  0.2   0:08.18 php5-fpm
 2431 www-data  20   0  344m  64m  908 R    2  3.2   0:04.23 apache2
 2435 www-data  20   0  304m  63m  836 R    2  3.2   0:03.43 apache2
 2413 www-data  20   0  349m  63m  920 R    2  3.2   0:07.51 apache2
 2465 www-data  20   0  349m  64m  944 R    2  3.2   0:05.04 apache2
 2518 www-data  20   0  307m  41m 1204 R    2  2.1   0:01.37 apache2
 2406 www-data  20   0  346m  56m 1144 R    2  2.8   0:03.76 apache2
 2456 www-data  20   0  345m  55m 1184 R    2  2.8   0:02.67 apache2
 2373 www-data  20   0  351m  63m  784 R    2  3.2   0:11.09 apache2
 2439 www-data  20   0  306m  35m  916 R    2  1.8   0:02.51 apache2
 2450 www-data  20   0  345m  55m 1088 R    2  2.8   0:02.96 apache2
 2486 www-data  20   0  299m  10m  876 R    2  0.5   0:01.19 apache2
 2523 www-data  20   0  300m  27m  796 R    2  1.4   0:00.99 apache2